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APRIL 14, 1934 NATURE 579 sa was correctly computed in five minutes, 510 in genes outweigh the female and the result is the twenty seconds and 610 in seventy seconds. normal haplo-X male." Division was a slower process and 9 digits divided Thus, as my italics show, the experimental by 3 took times varying from two and a half to geneticist seems to agree with what Prof. MacBride seven and three quarters minutes. has expressed in more generally intelligible language ; Square roots of 6 digit numbers were extracted in not only in admitting the essential sameness of sex less than a minute while cube roots took longer. in all organisms but also in understanding the Curiously enough, the memorising of a number of function of proportion in its determination in some 27 digits was not done successfully, although he of them. Unanimity among the different branches of could repeat questions which had been put to him biology has therefore been reached after a long period and their answers after some days had elapsed, and of divergence, from entirely different data and, what would break off calculations in the middle to ask for is more, apparently unawares. Such an event, surely, milk or cigarettes, taking up the calculations again should not be allowed to pass without notice and where he had broken off. His methods of working without applause. The usual view that the chromo­ were not discovered, but he had obviously memorised some theory of sex determination criticised by the squares of two digit numbers, and less completely MacBride was a special hypothesis put forward by the products of two digit numbers. McClung in 19024 and therefore not attributable to Though the arithmetical powers of this boy were Morgan, who accepted the hypothesis only in 191P, surprising, they were not comparable with those of should perhaps also not pass without mention. some of the calculating prodigies described by Rouse c. D. Ball in "Mathematical Recreations and Essays". John Innes Horticultural Institution, The boy was a good illustration of cases of arrest London, S.W.19. of mental development in which normal or even March 14. phenomenal mental capacity is observed in certain limited directions such as memory, calculating 1 NATURE, 133, 359, March 10, 1934. ' Qunrt. Rev. Biol., 6, 127 ; 1931. ability, musical ability, etc. He was so defective 'Amer. Nat., 56, 59; 1922. in respect to other mental faculties that he was ' Biol. BuU., 3, 43-74; 1902. • Science, N.S., 32, 839; 1911. unable to adjust himself to ordinary conditions of life, and became an inmate of the mental hospital. He died in the hospital at nineteen years of age. The autopsy disclosed that he had a softened patch, I AM delighted to find that such a distinguished probably an old hremorrhage, in the right occipital cytologist as Dr. Darlington "Though a long compass region of the brain, about the size of a small hen's round be fetched" has arrived at somewhat similar egg. A recent hremorrhage at the same place of the conclusions to those to which I myself have been led brain was the cause of his death. respecting the nature of sex. I do not, of course, H. W. DunGEON. view the 'gene' in the same light as he does, but H. E. HURST. Rince in an article shortly to be published in NATURE Cairo. I have given my views aR to the nature of the gene, Feb. 24. Dr. Darlington and I need not quarrel about the matter now. E. W. MAcBRIDE. Determination of Sex 43, Elm Park Gardens, THOSE who are interested in the heredity of sex Chelsea, S.W.lO. will be grateful to Prof. MacBride for again exposing March 17. in these columns' the naivete of some early views of this problem (which he attributes to Morgan). Especially will they be reassured by his conclusion. Ergine He points out that sex is essentially the same thing RECENTLY we showed' that the four ergot alkaloids wherever it occurs. He concludes :-"It seems clear (ergotoxine, ergotinine, ergotamine and ergotaminine) that there are fundamentally opposed male and by trAatment with alcoholic potassium hydroxide female constitutions, but that the constitution of give rise to a crystalline base ergine, which con­ every individual is a mixture of the two, and that stitutes about half the parent molecule. the structural manifestations of sex depend on the We have since proved that ergine is the amide proportion of these constitutions and on which gains of an acid, C 15H 15N 2 .COOE:, and further analyses of the upper hand in development" (italics mine). ergine and its salts show that the formula for ergine This view is somewhat similar to that reached by requires correction to C,.H170N 3 in agreement with way of experimental genetics. Thus Goldschmidt, the formula for the acid now isolated. reviewing his experiments since 19102 , states that Jacobs and Craig have published a paper2, in which "the resulting sex is dependent upon two genetic they have described the action of alkali upon ergotinine , somethings, one of which shifts sex towards the and the isolation of a crystalline acid, C 18H 160 2N 2 female, the other towards the male side". Again, which they name lysergic acid. We have no doubt Morgan's colleague Bridges3 says that "both sexes that this is identical with that prepared by ourselves are due to the action of opposed sets of genes, one from ergine. set tending to produce the characters called female, s. SMITH. and the other to produce the characters called male. G. M. TIMMIS. These two sets of genes are not equally effective, for W ellcome Chemical Works, in the complement as a whole the female-tendency Dartford, genes outweigh the male-tendency genes and the Kent. diploid (or triploid) form is a female. When the March 27. relative number of the female-tendency genes is 1 J. Chem. Soc., 1543; 1932. lowered by the absence of one X, the male-tendency 'J. Bwl. Ohem., 104, 547; 1934. © 1934 Nature Publishing Group.

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