ANIMAL PRODUCTION-. 573 



205). — This contains the rules which have been adopted by the egg committee 

 of the New Yorlj Mercantile Exchange. 



Double eggs, C. W. Hargitt (Amer. Nat., 7/6 (1912), No. '0-',9, pp. 556-560, figs. 

 3). — Two types of malformed eggs are illustrated and described. 



Investigations on crooked-breasted fowls, C. D. Stewart (Ann. Sci. Bui. 

 Roy. Agr. Col. Cirencester, 1911, No. 3, pp. 73, 74). — When both cock and hens 

 had this defect it was found not to be inherited in the offspring. As it was 

 produced by allowing chicks to rest on perches when young, it is thought that 

 unsuitable perches or perching at too young an age may be the cause of the 

 trouble. 



Preliminary note on crosses between pheasants and fowls, J. R. Ains- 

 worth-Davis (Ann. Sci. Bui. Roy. Agr. Col. Cirencester, 1911, No. 3, pp. 71, 72, 

 pi. 1). — A brief note on experiments in crossing a Mongolian pheasant cock with 

 goldeu-peucilled Hamburg hens, and an old English game bantam cock with 

 common hen pheasants. 



Sex-linked inheritance in poultry, T. H. Morgan and H. D. Goodale (Ann. 

 N. Y. Acad. Sci., 22 (1912), pp. 113-133, pis. S, figs. 4).— Grosses were malde 

 between Plymouth Rocks and Langshans»and the American Dominique and 

 Langshans. Data are reix>rted on barring, shank color, booting, down color, 

 white- feathered wings, and the color of bill and legs. 



A case of sex-linked inheritance in the domestic pigeon, L. J. Cole 

 (Science, n. sen, 36 (1912), No. 919, pp. 190-193).— This contains additional 

 notes to a brief report of work previously noted (E. S. R., 21, p. 274). 



Dun, yellow, and silver are considered as dilute conditions of black, red, and 

 blue respectively, and the phenomenon of dilutions in this case furnishes another 

 instance of sex-linked inheritance. A full report of the work is promised in the 

 near future. 



On the inheritance of tricolor coat in guinea pigs and its relation to 

 Galton's law of ancestral heredity, W. E. Castle (Amer. Nat., Jf6 (1912), No. 

 547, pp. 437-440). — The advantages of the Mendelian over the Galtonian inter- 

 pretation of tricolor inheritance in guinea pigs and in Bassett hounds are 

 pointed out. 



Physiological sex determination, B. C. Gruenberg (Science, n. ser., 35 

 (1912), No. 902, pp. 593, 594). — ^A criticism of the argument by Robinson 

 previously noted (E. S. R., 26, p. 773) that the suprarenal capsules are con- 

 cerned in the determination of sex. 



"A more general criticism of Robinson's argument lies in the tacit assumption 

 that sex differentiation means one thing in the higher vertebrates and man, 

 and quite a different thing in the rest of the animal kingdom and in plants. It 

 may well be that there are several distinct factors concerned in sex determina- 

 tion, bub these must all belong to related categories. It is extremely im- 

 probable that sex is determined by an accessory chromosome among insects, by 

 adrenalin among mammals, by traumatism among graminese, say, and by ultra- 

 violet rays among mosses." 



The present position of the sex problem, R. Hertwig (Biol. Centbl., 32 

 (1912), Nos. 1, pp. l-'io, figs. 7; 3, pp. 129-146). — A compendious summary of 

 investigations on the sex ratio, with special reference to Mendel's law and the 

 accessory chromosome. A bibliography is appended. 



Cell structure, H. Stauffacher (ZtscJir. Wiss. Zool., 95 (1910), No. 1, pp. 

 1-120, pis. 2, figs. 3; 98 (1911), No. 3, pp. 478-527, pi. 1, figs. 5; ahs. in Jour. Roy. 

 Micros. Sac, 1912, No. 4, p. 393). — Among numerous other studies on the struc- 

 ture of cells in the lower animals, the author finds more or less nuclein in the 

 nucleus of young ova but none in the nucleus of ripe ova. The head of the 

 spermatozoon in Anodonta was found to be full of nuclein, and it is suggested 



