THE JOURNAL OF THE LINNEAN SOCIETY, Notes on the Genera of Taxace@ and Con+ra. By MAXWELL T. MASTERS,M.D., F.R+S.,F.L.S., Corresponding Member of the Institute of France. [Read 15th December, 1S92.1 THE following observations are the outcome of a comparative examination of the morphological characters of all the genera of Taxacea? and Gomyem so far as I have been able to accomplish it. In most cases living plants have been examined, and in all instances the available museum and herbarium specimens have been studied and the literature relating tb them referred to. It is not necessary to state the sources whence I: have derived my information, as they are given in my paper on tbe Comparative Morphology of the Order, published in the Journal of this Society, Botany, vol. xxvii., and again in it List of Conifers and Tavads in cultivation in Great Britain, prepared for the Conifer Congress, and published in vol. xiv. of the Journal of the Royal Horticultural Society in October 1892. Constant reference has also been made to the schemes of arrangement proposed by the older writers, and in more recent times by Eichler, Van Tieghem, and others. In tho main, however, I have followed the lines laid down by Bentham, in Bentham and Hooker’s ‘Genera Plantarum,’ iii. p. 420 ef sep. (18SO). In LINN. J0TJRN.-BOTANY, TOL. XXS. B 2 DR. M. T. MASTEBS ON TEE some cases I have felt constrained to deviate from the arrange- ment there made, and to propose others which, according to my judgment, are more in harmony with ascertained facts or with more recently acquired information. Incidentally a few indi- cations of the structural peculiarities of certain parts, which may be available for purposes of distinction, are given, but any attempt to deal fully with comparative histology would be beyond the scope of the present communication. The writings of Ber- trand and of Van Tieghem may he specially pointed out as containing most valuable information on this head. Embryo- logical researches also are of the foremost importance from a classificatory point of view, but they demand for their prose- cution more time and skill than are at the command of the writer. It is, however, to systematic and comparative in- vestigation in these two departments, minute anatomy and embryology, that we must now look for future progress, but that progrcss will be retarded until the rigidly comparative and systematic methods by means of u-hich the framework of the Natural System has been pieced together shall be carried out aIso in histology and embryology. And this remark applies as strongly to the methods in which these observations are recorded and published as to the observations themselves. Classifications founded on leaf-structure, on the distribution of the resin- canals and fibro-vascular bundles, or on the structure of the wood even, without reference to all other evidence, are aeces- sarily as " artificial " as any other truncated schemes. For details concerning the structure of fossil species the reader will naturally refer to the publications of Williamson, Carruthers, and others. Por the indications as to geological distribution I am chiefly indebted to Renault and Starliie Gardner. TAXA C EB, Linclley, VegetaBbe Kingdom, ed. 3 (1853), p. 230. Arbores vel frutices. Rami plerumque hornomorphi raro dimorphi. Folia persistentia raro decidna. Plores mascoli amentiformes. Squamze fructifers, ut videtur, simplices, libera, membrariacea seu demum carnospe iiunquacl lignnospe. Ovula erects v. pcndula, e squamB emergentes, aril- lata vel raro arillo destituta. Testa sicca seu demum carnosa nunquam alata. GENERA OF TAXACEd AND CONIFERE:. 3 Tribus I. SALISBURINEB. Flores dioici; testa carnosa arillo geiiuino deficiente vel imperfecte evoluto. Ramuli dimorphi. Folk decidua. Flores masculi umbellati. ............. 1. GINKGO. Ramuli homornorphi. Folia persistentia. Flores masculi capitati .............. 2. CEPHALOTAXUS. Flores masculi spicati ................ 3. TOHREYA. Tribus 11. TAXINEB, wide p. 6. GINK 00, The earliest mention of this genus is by Kaempfer in 1112, and it was adopted by Linnseus, in his ' Mantissa,' ii. 313, in 1771. It is remarkable for its shoots, some of which are elon- gated, others contracted, its fan-shaped, many-ribbcd, deciduous leaves, and dicecious flowers. The male flowers are stipitate, catkin-like, arranged in umbels on the ends of branches, having short, contracted, or undeveloped internodes and intermixed with leaves. Anther-lobes two, pendulous, divergent, connec- tive prolonged iuto a knob. Pollen not seen. The female flowers are borne in pairs on the sides of slender stalks. each flower consisting of a single erect ovule destitute of bract or scale, but arising from a cup-shaped dilatation of the axis with- out any true arillus. The testa of the seed, however, eventnalip becomes succulent and drupe-like, while the inner coat becomcs hard and woody, as'in Qcas. The seed in the interior is covered with a brown membrane, the lower half of which is adherent to the shell, so that, on removing the latter, the lower part or" the perisperm is bared. A similar appearance is presented in the seeds of Cycas. As in the case of Toweya and Cephalotaxus, the structure of the ripe seed has a close resemblance to that of Cps, the nucellus having a well-marked pollen-chamber. According to Van Tieghem, Bull. SOC. Bot. France (1891), there are in the axis of the pith two resin-canals. The same author asserts that fertilization only takes place in the ripe seed after its fall in autumn, and that the embryo is only developed ip the following winter. The cotyledons, in germination, remain within the seed, their stallrs protruding in an arched manner, the cylindrical tigellum B2 4 DR. $1. T. MASTERS ax TEE or hypocotyl descending vertically into the ground, while the pirmule asccnds, bearing several scattered rudimentary leaves, arraiiged on the 3 plan beforc the perfect leaves are formed. Clustered raphides occur in the letires-a most unusual occur- rence iii Conifers. In the anatomical structure of thc root the inost striking feature is the abundance of callus-thickeiiiiigs in the angles of tlic cells of tlic endoderm. There is a single fibro-vascular bundle. The leaves ham no true palisade-cells, the two fibro-vascular bundles of thc petiole branch into several which traverse the lamina; each is ovoid in section, with xylem resting on tlic phloem. Wedge-shaped masse3 of sclerous tissue occur hcre and there beneath the epiderm, but no true exoderm. The genus is now represciited by a single Chinese and Japanese species, but was once so widely distributed through the colder and temperate parts of the northern hemisphere, that Prof. Heer enumerated no fewer than sixty species in the Secoiidnry mid Tertiary strata of various parts of the globe. It scenis probable that inost of these arc inere variations from a single species. CEPIIALOTAXJ 8. A genus first published in 18&0 by Siebold and Zuccnrini in their ‘Flora Japonica.’ The species are shrubs or trees with spirally arranged leaves, which, 011 the lateid branchcs, become tn isted into an apparently t\ro-raulrcd arrangement. The flowers arc dicecious, in stalked adlary heads, each flower subtended by a bract. Male flowers numerous, clustered, capitate. Anthers 3-lohed, pendulous froin the apes of the filament. Connective proloiiged. The female flowers arc bracteate mid arranged in termiiinl spikes or heads. The base of each bract becomes more or less fleshy, forming a cup-shaped cavity around a short shoot, mhich bears one or two erect ovules destitute of aril. The testa of the seed, however, becomes succulent, the inner lining bony, 60 that the ripe seed resembles a drupe, and is similar to the seed of C’GCISor of Gidgo,as described under the latter genus. In gerniination the seedling plant shows a thick fusiform tigellurn or hypocotyl, two long hear cotyledons, from between xxhioh the plumule emerges before the cotyleclons are disengaged from the seed-coats, as in Ciidyo, but the prima1.y leaves aro opposite and verticillate. GEXERA OF TAXIICEB MiD CONIFER&. 5 The lcaf-section (Cephalotaxus clrupncen) shows the inidrib prominent on tlic upper surface, a thick epiderm, no esoderm, and a single laycr of palisadc-cells above the rnesophyll. Inthe centre is the fibro-vascular bundle, in section, of an elliptical shape, with ill-defined endoderm. Iiniiiediately beneath the phloem is a siiigle central rrsin-canal, between which and the lower epiderm two or three ron s of cells iutervenc. The stomata are abundant on the lower surface; they are of the usual reniform shape, and are arrangcd in linear serics. Van Tieghein notes the presence of a resin-canal in the centre of the pith, a character which separates it from a11 Conifers except its iiear ally Ginkgo, wliich has two in the same situation (Bull. SOC.Bot. France, 1891, April 24). By Bcntliam and IIooker tiiis genus is placed among the TnxocZiizece. It is, however, evident that its nearest affinity is \\ith Ginkgo and Towvqa, aud that it has relatively little in coii3mon with Y’uxodinee. The spccies are natives of China arid Japan, extendiug into Khasin. TORREYA. A genus established by Arnott in 1838, in Ann. Nat. Hist. Rer. 1, vol. i. p. 130. The leaves are spirally disposed, the flowers dicecious. Thc male iloTTers are axillary, spike-like, surrouudcd at tlie baso by imbricate scales ; each stainen has a filament which expands at its upper portion into 2-4 longitudinally deliisciiig pollen-sacs ; connective slightly prolonged. The feinale flowers are solitary, axillary, Kith imbricating, rather fleshy scales at the base. The erect ovule is gradually invested from below upwards by a fleshy aril, which becomes confluent with the succulent testa, so that in the ripe seed it is no longer distinguishable.