A PLANTSMAN'S DETECTIVE STORY FRONTISPIECE. In Japan the skin of an called the is widely used as a seasoning for cooked foods, and the extracted juice serves as a condiment, much as we use vinegar. The Yuzu is found semi-wild in southern Japan, and was long supposed to have been indigenous to that region. Among the many discovered by Frank Meyer in China was a wild orange which he called the Kansu orange, after the province of Central China in which it was found. Plants of this orange were raised in the greenhouses of the United States Department of Agriculture at Washington, and they were found to be surprisingly like the plants of the Yuzu growing there. Examination of Meyer's photographs and botanic material revealed the interesting fact that the Yuzu and the Kansu orange were identical, thus establishing the interesting fact that this useful Japanese had been imported from China a great many years ago. This is the field photograph made by Meyer of the fruit of the Kansu orange. (See text, p. 245.)

Downloaded from https://academic.oup.com/jhered/article-abstract/13/6/243/766907 by University of Durham user on 12 March 2018 OF JAPAN With Notes on Their History and the Origin of Varieties through Bud Variation1 TYOZABURO TANAKA Office of Crop Physiology and Breeding Investigations, U. S. Department of Agriculture - HEN the citrus fruits of Japan THE SATSUMA ORANGE Ware discussed, attention should be The leading orange grown in Japan called to the fact that orange is a kind of mandarin, Unshii Mikan, culture is one of the leading industries called the Satsuma orange in the of my country, producing fruit of ex- United States. This variety forms cellent quality and delicious flavor, nearly seven-tenths of our entire orange with an annual return of more than crop. The fruit of the Satsuma differs fifteen million dollars. Other fruits, from the King orange in its soft, thin, like persimmons, plums, apples, rind of a bright orange color, and in its peaches, sandpears, and cherries are extremely sweet pulp. The leaves of cultivated extensively, but none of the Satsuma are very large and droop- them rivals the orange, thanks to the ing, with the petiole devoid of con- climatic conditions of the island, which spicuous marginal wings. From com- throughout a large part of central and mon the Satsuma orange southern Japan seem more favorable is easily distinguished by the absence to orange culture than to any other of the scarlet or vermillion tinge which fruit industry. characterizes the rind of the tangerines. In consequence of the utilization of The Satsuma also is distinguished by flat areas for rice plantations, oranges the well developed calyx-lobes of its are mostly planted on the slopes of flowers and in its very fine-grained, hills, the sides of which are terraced melting pulp, which is of good keeping on a great scale, using heavy stone walls quality. to retain the soil. This orange is now raised in the The operations of planting, cultiva- United States, principally in Alabama tion, fertilization, picking, hauling, and and other Gulf States, the Satsuma packing, are all carried on by hand, orchards in the Mobile Bay District without the aid of heavy machinery. alone covering an area of about 12,000 The fruits are shipped to markets and acres. Its future is highly promising,, to centers of distribution by railway owing to the favorable climatic condi- or by boat. tions of the region into which it has Systematic methods of selling have been introduced, and also to the exis- developed in recent years in many tence of well organized business regions, and large packing houses and methods for handling the fruit. To storage plants are constructed either by the more efficient development of the individuals or by cooperative associa- Satsuma orange industry in this coun- tions of farmers. Within recent years try the Office of Crop Physiology and the exportation of citrus fruits to the Breeding Investigations is now direct- United States and Canada has been ing some attention, endeavoring espe- carried on under strict Government cially to introduce improved strains of inspection, with every precaution varieties into actual cultivation. against the dissemination of injurious insects and fungus diseases; but owing NATSU-, A LARGE SUMMER to our own excellent home market, the ORANGE export trade has not developed into an The second important orange of important enterprise. Japan is the Natsu-daidai. This is a 1 Read before the 160th Regular Meeting of the Botanical Society of Washington, at the Cosmos Club, May 2, 1922.

Downloaded from https://academic.oup.com/jhered/article-abstract/13/6/243/766907 by University of Durham user on 12 March 2018 FRUITS OF THE WASE ORANGE FIGURE 1. These oranges were bo.ught in the Kobi market, Japan, on the third of November, 1919. They were forwarded to Washington where they arrived December the fifth, and this photograph was taken one month later. This was at least two months after they had been picked, during which time they had been shipped half way around the globe. The fine condition they were still in when photographed testifies to the remarkable keeping qualities of this variety. (See text, p. 251.) Photograph by E. L. Crandall.

Downloaded from https://academic.oup.com/jhered/article-abstract/13/6/243/766907 by University of Durham user on 12 March 2018 Tanaka: Citrus Fruits of Japan 245 large summer orange about the size Besides these well-known kinds of and shape of a ; but it differs oranges, a number of local varieties or from the grapefruit in its more pitted fancy fruits are to be noticed, for in- skin, which is of a deep -yellow, stance Anado and Tengu, attractive and in its coarse-grained, slightly for its red skin, but with rather insipid bitter pulp, which matures in late soft pulp; Naruto and Sambo, yellow spring. It is inferior in quality to a skin oranges of late maturing, with good grapefruit, but its extremely hardy good flavor; Koji, and Suruga-ynkd, nature and its resistance to citrus very early maturing small fruits of ex- canker are appreciated by growers, tremely smooth surface; Keraji Mikan as well as its admirable sturdiness of Kikai island, with very early matur- which enables it to withstand rough ing and extremely fragrant yellow treatment. fruit, Hyilga Natsumikan, with very late-maturing and very juicy medium- THE WASHINGTON NAVEL ORANGE sized fruits. The third important variety of orange is the Washington navel orange A MYSTERY SOLVED THROUGH A which was first imported into Japan in INTRODUCTION 1891. It was absolutely new to the Mention should be made of an orange Japanese growers when it was first highly esteemed for seasoning cooked introduced, and much attention has food, that is Yuzn, first called Citrus been paid to the development of the Jonos, by Siebold, in his Synopsis navel orange industry, but owing to the Plantarum Oeconomicarum, published humid atmosphere and lower temper- in 1830. This plant grows semi-wild, ature, it was found not to do so well in southern Japan, but is commonly as in southern California. Recently planted in the yards of farm houses for Japanese farmers have learned a special its fruit. The peel is highly aromatic, method of treating the plant, which and for flavoring cooked dishes and checks its vegetative overgrowth and soup or fish it is superior to or increases fruiting by means of severe limes. The juice is used extensively in pruning or dwarfing, like the treatment the place of vinegar for seasoning raw of lemon trees in Italy. The good food and salads. Two hybrid varieties keeping quality of the fruit made it of Yuzu, Yuko and , are ex- especially desirable, and the Japanese tensively cultivated in Shikoku Island were loath to give up its cultivation. for vinegar substitutes and also for Other kinds of sweet oranges are manufacturing . plentifully produced in the southern In 1915, Frank N. Meyer, the great part of the Kyushu Island ; but they do agricultural explorer of the U. S. Dept. not reach the central markets, from of Agriculture, found a wild orange which native pummelos and shaddocks in Kansu, China, which he imported are also absent. Over two hundred into this country under the provi- varieties of sweet oranges and pumme- sional name "Kansu Orange." After a los are estimated to exist in Japan close comparison of a green house proper, and a number of promising plant of the Kansu orange with the shaddocks, like Hirado, Egami, or Yuzu, together with an examination of Ogami, are of sufficient importance to Meyer's photographs and notes, the be multiplied for economic cultivation. writer found the two to be identical, A very prolific mandarin called Yat- thereby proving this extremely useful sushiro is often found in cultivation orange to be of Chinese origin. and the common China mandarin, The seeds of Yuzu are sometimes called Kishti Mikan, or Kinokuni in used for raising stock plants for the this country, is more or less extensively Satsuma orange, and it is believed by grown. Kunembo, a variety of the the farmers that plants grafted on King orange, is also commonly raised Yuzu stock live longer and behave in southern provinces. better than those grafted on Trifoliate

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orange under certain local conditions, extensively manufactured by proprie- especially on hill-top situations where tary medicine corporations and con- the available surface soil is apt to be spicuously advertised on signboards very thin. throughout the Orient. STOCK PLANTS AN EARLY AGRICULTURAL EXPLORER For stock plants, Japanese growers Having enumerated the principal use the almost ex- citrus fruits grown in Japan, I turn now clusively, on account of its hardiness to the question of how this remarkably and the cheapness of the seed, for this large number of varieties were intro- species is extensively planted in hedges duced into actual cultivation. The surrounding houses. Owing, however, first citrus fruits introduced into Japan to its high susceptibility to citrus came from China or from some other canker, the farmers are having recourse country of southern Asia. We have to other species as stock for grafting two historical accounts of their intro- navel oranges and other varieties of duction. The most reliable, written sweet oranges. The sour orange, or in the Kojiki, or Record, compiled by Seville orange, is also grown for its Ono Yasumaro about 712 A. D., tells juice and seeds. It furnishes a vine- of the famous expedition of Taji gar substitute, not as good as the Mamori, who was sent abroad by the juice of the Yuzti. Emperor Suinin in the year 61 A. D. A half-wild pummelo, Yama-mikan, and returned to Japan after an absence resembling grapefruit more than any- of ten years, bringing back eight leafy thing else, is also used as stock in the branches and eight leafless branches of southern part of Kyushu island, like citrus fruits. When he arrived at .t).-.e pummelo stock in this country. Re- imperial court he found ..that the cently experiments have been made Emperor was no longer living, and in with Rusk at stations co- his grief he took his own life, after operating with the U. S. Department having presented at the Emperor's of Agriculture. This stock, it is hoped, tomb the fruits of his travels which will bring considerable improvement he had hoped to lay at his Sovereign's in the propagation of orange trees in feet. jj:./' Japan. Nothing is known of Taji MaiW"u itinerary during his ten years.of..'• THE KUMKJUAT dering in southern Asia, arid' For prer 01 Ornamental fruit account of the fruit he brought back the kumquaj. is grown in various locali- with him is obscure. According to ties. This is a small fruit with sweet the Nippongi, a chronicle compiled by peel and a pleasantly acid pulp. It Toneri Shinno in the year 720 A. D., the occurs in several varieties or forms, orange introduced by him was the such as the Marumi, or round kum- Tachibana, the name of which was quat, the Nagami, or oval , supposed to be a modification of and the Meiwi; or large round kum- Tajima-na, signifying "Named after quat. Besi .he kumquat the thick Tajima." This explanation, however, rind of puiiiii.elos is also preserved in is hardly possible; for the Tachibana, sugar, mak'J .g an excellent candy with now occasionally seen as a sacred plant a flavor of its own. Sliced Satsuma in the court yards of Shinto shrines, fruits candied in sugar are also ex- grows spontaneously and abundantly tensively manufactured in southern in southern Japan, where it appears to countries. They make an attractive be indigenous. The fruit of the sweetmeat with a delicious flavor. The Tachibana is insignificant from an dried peel is also used in the prepara- economic point of view, and the tree tion of various kinds of drugs. Orange is of no importance except for the orna- peel and persimmon calyces are the mental value of its small bright yellow source of a celebrated tonic pill, fruit, which is too acid to be used for

Downloaded from https://academic.oup.com/jhered/article-abstract/13/6/243/766907 by University of Durham user on 12 March 2018 Tanaka: Citrus Fruits of Japan a47 food. The primeval forest of Tachibana Flowers and fruits were formerly found at Tsuro-mura, in the country strung into garlands and necklaces by of Aki, prefecture of Kochi, has been the ancient Japanese, as they still are officially registered as a Natural Monu- strung by the Hawaiians of the present ment Reservation of Japan. The day. This ancient custom :^ connec- grows wild in great tion with the fragrant Llos^jms and abundance not only in the prefecture golden fruits of the Tachibana is com- of Kochi but also in the province of memorated in the following verses, Hyuga, and a locality named after the written in the eighth century of the Tachibana appears in the earliest Christian era, when the Anglo-Saxons mythology of Japan.2 were still pagans and European litera- ture was at its lowest ebb. THE TACHIBANA Satsuki no hana Tachibana wo kimi ga tame The handsome fruit of the Tachibana Tama ni koso nuke chiramaku oshimi. orange and its fragrant blossoms have for centuries been celebrated in poems May offers thee fair Tachibana flowers, Like beads to string into a garland sweet. by the Japanese, in whose coats of Oh hasten, lest the fleeting hours arms they also appear. Some of these May strew them withered at thy feet. poems are given in the Mannyoshu, -0O0- or "Myriad Leaf Collection," a most Waga yado no hana Tachibana no itsunikamo brilliant relic of the ancient people of Tama ni nukubeku sono mi narinam. Japan, compiled about the year 750 My Tachibana's fragrant flowers of spring A. D. It might be interesting to quote Caressed by summer's fervid, quickening air the following poems, in which so many Have borne fair fruits, like beads of gold, to ce. "ips ago the Tachibana is named. string These, like all Japanese poems, are In necklaces to grace my lady fair. characterized by their brevity. Each These ancient verses show that the poem is a single thought embodied in Tachibana is not an imported plant, a certain number of lines each com- but one that has grown in Japan for posed of a definite number of syllables. many centuries. The identity of the "'"?imogo ga yado no Tachibana ito chikaku citrus fruit introduced by Taji Mamori hi yue ni narazuba yamaji. still remains in doubt. That he did bring a foreign plant into the Island .-n."/ be rendered as follows: Empire about th"; year 70 of the u My lady's cottage very near Christian era can. be ques- I set a Tachibana tree, tioned; for the incitieuL.. A his cele- That its bright fruits from year to year brated expedition and his Lragic death Might tell her of my constancy. form one of the most important chap- Another poem pictures the Tachibana ters of the Chronicle handed down to in bloom: us. This early account of an agricul- tural explorer sent on a mission for the Waga yado no hana Tachibana ni Hototogisu purpose of discovering and bringing Ima koso nakame tomo ni aerutoki. back desirable plants his native Oh Cukoo, in my blooming Tachibana tree, country deserves to ran. ^th that of Sing loud with joy! My friend has come to me. the Queen Hatshepsut's t ^edition of

5 In the account of the Creation, Izanagi, the Adam of Japan, had become separated from Izanami, his Eve, and sought her in every corner of the world. At last he went to the land of Darkness, where he found her indeed, not in the perfection of her loveliness, but in the form of a repulsive corpse, whose touch was pollution. He could not conceal his horror on beholding her, and in her fury she called upon the devils of Hell to expel him. On coming forth into the land of Light, the first act of Izanagi was to purify his body at a place, which the myth calls Tachibana no Odo, in the province of Hyuga. On washing his right eye a god was born, Tsukiyomi-no-mikoto, the Moon God. On washing his left eye, behold a bright aurora emanated from it; this was Amaterasu, the Sun Goddess, the first Ancestor of the people of Nippon. Thus is the name of Tachibana associated with the very beginning of our race.

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1570 B. c, recorded in the hieroglyphics however, like Shuo wen, the ancient of Egypt and that of Chan Ch'ien, who dictionary compiled by Hsu Shen in imported alfalfa and the grape into the first century of the Christian era, China about the year 126 B. C. TO and the Powuchi ("Record of remark- these early explorers the agents of our able objects") written by Chang Hua, own Office of Foreign Seed and Plant who lived 232-300 A.D., there are Introduction are worthy successors. descriptions of the Yu tz'u growing in About twenty years ago relics of China, which correspond to the orange an ancient shrine dedicated to Taji with acid pulp which bears this name Mamori were discovered in the village in Japan. The Yuzu plant is fairly of Kamo-mura, county of Kaiso, pro- well illustrated in the Atlas of Shao vince of Wakayama. Thanks to the hsing pen ts'ao or the 1159 edition of enthusiasm and piety of Toranosuke the famous Cheng Lei herbal, quite Mayeyama, a citrus grower of the lost in China but existing in manu- village, a new shrine was built and script copies restored in Japan. In all several stone monuments were erected probability the name was applied to on the site of the ancient relics, and the acid Yuzu orange introduced into recently the village council passed a Japan from China and that the original resolution to establish a new plant- Chinese name Yu tz'u gradually became introduction garden and citrus experi- obsolete in China itself. mental orchard near by, in memory of Tajima's expedition and to emphasize THE SWEET KUMQUAT his patriotic spirit to benefit his coun- Concern'ng the introduction into try through the introduction of desir- Japan of the sour orange, shaddock, able foreign plants. It is interesting sweet orange, Kdji, of the to see the development of such an group called Beni Mikan in Japan, idea which had not before been thought and the common kumquat, we have no of great importance. record. In all probability they came Going back to another record of to our shores on board visiting mer- introduction of a citrus fruit into chant vessels, as in the well-known case Japan, attention is called to an account of the large round kumquat now called in the Shoku Nihongi, or Supplemen- Fortunella crassifolia by Swingle. This tary Chronicle, completed in the year improved kumquat was accidentally 797 A. D. under the supervision of the brought to us by a shipwrecked Chinese Emperor Kwanmu, stating that in sailor of Ningpo, cast ashore at Miho, 725 A. D. the Emperor Shomu bestowed near the port of Shimidzu, Shidsuuoka- upon Harima no Otoe the Fifth lower ken, where he was rescued by the na- junior rank of the Imperial Court on tives. A preserved kumquat, which account of his successful importation the shipwrecked man carried in his of citrus fruits from China and the pocket, yielded seeds which were propagation of these plants in Japan. planted in a private yard, and which The name of the orange alluded to was proved to be a type of fruit tree quite written in Chinese Kan ts'u which new to Japan. This happened during corresponds to the Kinokuni Mikan the Meiwa period, that is, between now grown in many places. 1764 and 1771, and the Japanese name Meiwa Kinkan, or Neiha Kinkan, was INTRODUCTION OF THE YUZU accordingly applied to this variety. No record of the introduction of the The original parent of the Meiwa Yuzu has been discovered. This name of Japan is still growing in Yu tz'u in Chinese is now used exclu- the place where it was first planted. sively to designate shaddocks in south- ern China and Formosa. It is not gen- ORIGIN OF THE SATSUMA ORANGE A erally used in Chinese for the acid MYSTERY citrus fruit so well known in Japan The Satsuma orange, most important under this name. In certain old works, of all fruits, is called

Downloaded from https://academic.oup.com/jhered/article-abstract/13/6/243/766907 by University of Durham user on 12 March 2018 Tanaka: Citrus Fruits of Japan 249 Unshu Mikan in Japan, the orange observed. These instances show that of Wen Chou, province of Chekian, the Satsuma orange is a variety which China. The first valid name applied has been known to the Japanese for at to this orange was that proposed by least 300 years, although its cultivation Okamura Shooken in his manuscript on an economic scale was not under- work Keien Kippn (Monograph of Cit- taken until about 40 years ago. It is rus) written about the year 1828. It entirely unknown in China. A local gives a good description accompanied tradition current in the prefecture by an excellent illustration. The name Fukuoka attributing its origin to the Unshu had before that time been used in Taiko Korean Expedition of 1592— earlier works but it had been applied 1597 is in all probability erroneous; to varieties quite different from the since the climate of Korea is too severe common Satsuma orange. The Yamato for oranges of any kind. Honzo, or Japanese Herbal, of Kai- It might be supposed to be of hybrid bara Ekken, published in 1709, applied origin, like many other cultivated the name Unshu to a variety with small fruits, were it not for the fact that the thin leaves and fruit as large as the Satsuma has not a single character in Kino-kuni Mandarin, with fed rind. common with any other known orange. This description does not accord with Kunembo, a botanical variety of the the characters of the true Satsuma. In King orange, and the Yatsushiro are the Japanese-Chinese Cyclopedia, most nearly like the Satsuma in general called Wakan Saisai Dzue, a work appearance, but botanically they are written by Terajima Ryoan and printed quite remote from it. The Satsuma is in 1714, a citrus fruit called the Unshu really a good botanical species, though is mentioned but its leaves are de- botanists may hesitate to give it a scribed as resembling those of the Yuzu specific name until the mystery of its and its fruit, of the size of the Kino- origin has been solved. Like maize or kuni mandarin, and as having a thick Indian corn, its ancestry has not yet peel and acid pulp. This description been fixed; but it seems advisable to does not apply to the true Unshu of regard it as a distinct horticultural Japan. The earliest occurrence of species with a specific name of its own. It the name Unshu in Japanese literature seems to me after twelve years' experi- is in a work called Teikin Orai ("Fam- ence with citrus fruits, that the only ily letterwriting") compiled by a Bud- possible way to treat the group botan- dhist bonze named Gen'e Hoin in the ically is to regard a number of the 14th Century. The name also occurs distinct forms as horticultural species. in the Kagakushii, a dictionary of primary learning compiled by another ORIGIN OF NEW TYPES OF CITRUS bonze, Toruku Hatotsu in 1444, but FRUITS as there are no descriptions of the fruits mentioned in these works it is I come now to the discussion of the impossible to fix their identity. A origin of new types of citrus fruits. very old Unshu, or Satsuma orange The activities of the Office of Crop tree, which grew in the small village Physiology and Breeding Investigations of Fukutoma-mura, in the prefecture of the United States Department of of Fukuoka, died in the spring of 1920. Agriculture have resulted in the devel- Its age was reputed to be 300 years or opment of thousands of new forms by more. The oldest living plant which I means of artificial hybridization and have seen was one in the prefecture of selection. It is therefore quite natural Oita, growing to a height of 25 feet to think that hybridization is an impor- with its branches spreading over an tant method of obtaining a desirable area of about 40 feet in diameter. It novelty. Orange hybrids may some- must have been at least 200 years old. times lose the parental characters The vestiges of a similar tree which entirely by assuming an intermediate had fallen in recent years were also form; but among hundreds of plant characters there must remain some

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POT-GROWN PLANT OF WASE SATSUMA FIGURE 2. It is not known how the Japanese Satsuma orange originated, but it has been cultivated for at least three hundred years. Concerning the Wase variety, we know quite definitely that it was discovered about twenty years ago as a bud sport of great promise in a grove of oranges on the Island of Kyushu. The fruit of the Wase is large and flat and matures much earlier than the other varieties of Satsuma orange. Photograph by E. L. Crandall.

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which will behave as Mendelian domi- and flat fruits. From the latter is nants. For instance, the hairiness of segregated a strain with very large of the ovary, the trifoliate form of the leaves, and large, flat fruits. This is leaves, and the existence of oil in the generally called, by the Japanese pulp vesicles are in many cases Mendel- Kairyo, or improved Unshu. Another ian dominants in crosses between the striking variety, of promising eco- trifoliate and other kinds of oranges. nomic value, is the Wase, first found The strong aromatic substance in the in the village of Aoe on Kyushu Island, rind of the Yuzu is also inherited with- about twenty years ago, and now rank- out much reduction by its offspring. ing highest among all the oranges in Wedge-shaped seeds and the well- the market. The discovery of the Wase developed marginal wings on the peti- orange was just an accident, but its oles of the leaves of pummeloes are development into an important indus- also handed down in varying degrees try was due to the keen business mind to their descendants, and in addition to of the Japanese farmer. Just how these these, other dominant characters could different varieties originated is not be enumerated. known; but one thing is quite certain, It is difficult, however, to explain the they are not of hybrid origin origin of some of the characters which With the encouragement and help of make their appearance, as the absence Mr. Walter T. Swingle, I took up the of seed in the Satsuma and the Wash- study of citrus fruits in the hope of ington navel orange. In the flowers of securing the best type of large-fruiting, these oranges the male or staminate early-maturing strains of the Satsuma organs are absolutely abortive, and orange in Japan, which might prove of sometimes the female or pistillate value to growers in the Gulf states of organ lacks the function of fertiliza- this country. In the American mar- tion. Vegetative nucellar tissue may kets, as everybody knows, fruit is very develop into the embryo without the scarce from October 1st to November intervention of spores. This phenome- 15th; if ordinary varieties of Satsuma non is generally called apogamy. The are raised, the markets of this season seed thus formed when planted pro- can partly be supplied by fruit from duces a plant exactly like the female the groves of Alabama. In 1920 the parent, whether it has been subjected first carload of Satsumas was shipped to cross-pollination or not.3 A great as early as November 11th. During the many plants produce seed by apogamy, last year it was possible to ship this and all efforts to obtain hybrids by fruit as early as October 23, using cross pollinating them are ineffective. artificial methods of curing. There still Hybridization, therefore, cannot be the remains a period of 20 days when, only way to create new horticultural oranges are very scarce in the American varieties. In. the Satsuma orange market. In this connection attention is there are several, distinct groups or called to the fact that Japanese citrus sections, which differ from one another, growers ship the fruit of Wase oranges in some cases by the habit of the tree, as early as September 20. in others in the shape and size of the Wase is a very distinct fruit, char- leaves, in others in the time of ripening acterized by large round form, ex- the fruit, or perhaps in the appearance tremely thin, polished rind, and very of the fruit itself. abundant coarsely grained pulp (see Fig. 1). Its leaves, petioles, dormant buds, THE WASE SATSUMA flower-buds and calyx characters are One group, called Ikeda, has numer- quite different from all other strains of ous small leaves and round fruits; Satsuma, so that it may well be re- another called Owari, has larger leaves garded as a good botanical variety.

3 SWINGLE, W. T. and T. R. ROBIXSOX. A New . Journal of Heredity XII: 151-153, April, 1922.

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NEW VARIETIES BY BUD VARIATION Wase to revert to the parental Owari 4 The oldest Wasi tree, now about 70 form. years of age, is found in the village of Aoe, prefecture of Oita. Three younger TENDENCY TO REVERT plants from which the present com- Early growers of commercial Wase mercial variety was taken, also exist in trees noticed that a certain percentage the same village. All of them are of their plants did not come out as grafted, and we know not whence they Wase, but reverted to the Owari type; came; but the discovery of almost and they suspected that there was some exactly the same form of orange on a mistake made in selecting the budwood. branch of an entirely different kind of Later it was observed that Wase trees Satsuma, threw a new light upon the sometimes send forth branches bearing question of the origin of varieties. In leaves and fruits quite different from the village of Tsukumi, not far from those of the typical Wase, but closely Aoe, a farmer discovered very early- resembling the ancestral Owari forms. maturing fruits borne on an ordinary These are clear examples of vegetative Owari Satsuma tree. A careful study reversion, which is known to occur only of the fruits and flowers of this tree by in a limited number of cases on bud the writer proved this early variety to sports, or varieties resulting from mu- be identical in all respects with the tation. A careful study of this phenome- Wase originating'at Aoe. It was a non convinced me that it is very clear case of progressive or beneficial common in the Wase of Aoe. To cite bud-variation. It is of great interest an extreme case, twenty-seven trees to note that variations of this kind are out of one hundred were found to by no means very rare; they are, on bear branches having the character- the contrary, rather to be expected, as istics of the ancestral form on which the a careful study of the phenomenon has variety had appeared as a bud varia- shown. In the villages of Hisatomo tion. This demonstrates the impor- and Ocho, in the prefecture of Hiro- tance of selecting with the greatest shima, on the inland sea, other strains care the buds to be used for propagat- were found which had likewise origi- ing. nated from bud variation. The charac- ters of the new Wase growing in these Whether the Wase is a real somatic places, are slightly different from one mutant or a "chimera" we know not. another, as well as from the Aoe and If a chimera, its reversion to the Tsukumi Wase. In four different ancestral form can easily be explained; villages of the prefecture of Shidzuoka, for most chimeras behave in the same I found different strains of Wase, way. At the same time we must which had undoubtedly originated expect the occurrence of unchangeable from bud variations. These bore a Wast by a similar procedure. We general resemblance to one another, do not know whether or not absolutely but when carefully studied, all of them constant Wase exists; but of one thing proved to be distinct. Some of these we are quite certain, that bud variation new varieties have been propagated and vegetative reversion are associated by grafting and their progenies have, phenomena in plants belonging to the in all cases, been found to possess the genus Citrus, and this may also be true new characters without alteration. with mutants of other plants not in- Commercial orchards of the Wase cluded in the family , though variety, descended from trees of the in this connection our knowledge is still village of Aoe, also continue in the scanty. Variegated leaves associated main, true to type, but it is especially with striped fruits originate by bud interesting to note the tendency of the variation; and it is well known that in these variegated forms reversion to

• TANAKA, T. A New Feature of Bud Variation in Citrus. Circular 206, U. S. Department of Agriculture. 1922.

Downloaded from https://academic.oup.com/jhered/article-abstract/13/6/243/766907 by University of Durham user on 12 March 2018 Tanaka: Citrus Fruits of Japan 253 plain color is quite common. Willow- plants is full of interest to the natural- leafed forms associated with elongated ist. The case of the Wase orange is one fruits also occur from bud variations of the most interesting in this connec- and often revert to original normal tion, not only to the student bent upon types. discovering nature's secrets, but also to Perhaps the most striking case of the horticulturist ready to apply such vegetative reversion is presented by discoveries to the material advantage of the corrugated form of Shuji Mikan, mankind. Nature is always ready to or Spicy Mandarin, in which two dis- respond to our appreciation and to tinct forms of fruit and leaves are reward our interest in her laws. It is always found simultaneously on the to the agriculturist that she seems same plant. These instances suggest ready to yield her richest treasures. the probability that a closer study of In conclusion may I quote an ancient bud sports and sexual mutants will Japanese poem which presents this very reveal the secret of reversion, the thought: phenomenon opposite to original muta- tion. Attention is also called to the "Ametsuchi no Megumi wa tsuneni mujinzd important roles which these phenomena Kuwa de horitore, Kama de karitore." may play in the evolution of living which may be rendered in English: organisms, and in the solution of the great problem of the origin of species. "To mankind boundless wealth is given By fertile Earth and gracious Heaven. The study of natural phenomena Then dig ye deep into the mold through the behavior of our economic And reap your crop of burnished gold."

The Place of Heredity in Biology FOUNDATIONS OF BIOLOGY, by LOR- with the following summary:—"In ANDE L. WOODRUFF, Professor of the first place, it appears clear that the Biology in Yale University. Pp. basis of inheritance is in the germinal 476, 211 figures. New York, The rather than in the somatic constitution of the individual. A character to be Macmillan Company. 1922. inherited must be innate in the germ It is of genetic interest to find that cells, and there is no satisfactory evi- Professor Woodruff, in putting together dence that modifications of the body, what he considers as worth while for 'acquired characters,' can be trans- "the college student and the general ferred to the germ and so inherited. reader" after several years of experi- Secondly, characters or groups of ence in teaching young men at Yale, characters are usually, if not univer- has placed unmistakable emphasis upon sally, inherited as definite units. These heredity as one of the important follow Mendelian principles of segre- "foundations of biology." This em- gation and recombination in the forma- phasis did not characterize biological tion of the germ cells of an individual, textbooks of a generation ago. so that paternal and maternal con- The chromosome cycle, mutations, tributions are readjusted in all the Mendelism, sex-determination, linkage combinations which are mathemati- and pure lines are among the many cally possible. And, finally, the germinal topics that are rescued from the closet factor basis (genes) of unit characters of the specialist in this excellent book is remarkably constant. Selection is and made common intellectual prop- apparently powerless to alter it, but erty. merely sorts out what is alreadythere, The chapter upon "The Heritage of or, taking advantage of such changes the Individual," in which the task of (mutations) as do occur, determines selecting the important and discarding their survival value for their possessor the irrelevant in the field of heredity in the struggle for existence." has been admirably carried out, closes //. E. W.

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SUPERBA AND ITS PARENT TYPE FIGURE 3. Nephrolepis hirsulula, of which superba is a variety, grows wild only in the Asiatic tropics. Its fronds somewhat resemble those of the sword fern (Fig. 7), but they differ in several respects. The prize for the fern with the most beautiful fronds would undoubtedly go to N. superba, the pinnae of which are ruffled and lobed in an exquisite manner. Unfortunately this form and all varieties of N. hirsulula can be grown only under the most favorable greenhouse conditions, so that it is entirely unsuitable for cultivation by commercial growers, and by most amateur plant fanciers. (See text, p. 257.)