ANIMAL PEODUCTION". 275 



gested that there may be some means of control' iiiy the chemical environment 

 of the developing germ. 



On Mendelian dominance, A. R. Moore (Arch. Entwickl. Mech. Organ., 

 Slf (1912), pt. 1, pp. 168-175, figs. 9).— In support of a hypothesis, previously 

 noted (E. S. R., 23, p. 778), the author cites a number of experiments with in- 

 vertebrates by which incomplete dominance can be explained on biochemical 

 grounds. 



"According to our hj^pothesis that the substances underlying the formation 

 of dominant characters obey the laws governing enzym reactions, we should 

 expect these reactions to go forward at a slower rate in the heterozygote than 

 in the pure dominant because the former contains but one-half the amount of 

 enzym to be found in the latter." 



A simplified method of calculating frequencies of occurrence from a 

 large number of unequal probabilities, A. G. McKendrick (Biometrika, 8 

 (1912), No. S-ff, pp. J,13~.'fl9). — This biometric method of determining whether 

 the distribution is regulated by laws of chance or by other factors is illustrated 

 by applying it to a study of the recurring attacks of disease in epidemics. 



Factors affecting the secondary sexual characters, E. Steinach (Zentbl. 

 Physiol., 24 (1910), No. 13, pp. fiol-r.dO; 25 (1911), 17, pp. 723-725; Jour. Amer. 

 Med. Assoc, 58 (1912), No. 7, p. 484). — Testes and ovaries of rats and guinea 

 pigs were transplanted into eai'ly castrates of the same and the opposite sex. 

 The tissues maintained their integrity and exerted an influence on the sex 

 characters. Neither the somatic nor the psychic secondary traits were fixed in 

 the individual. Thej' developed under the domination of the respective glands 

 which were present and functionally active. 



Contribution to the study of experimental determination of sex, 

 I. BoNAZZT (Arch. Ital. Biol., 56 (1911), No. 3, pp. 433-447, figs. 8).— Following 

 the methods used by Ducceschi and Tallarico ^ an orchitoxic serum obtained 

 from sheep was injected into rabbits. It was without apparent influence on 

 the sex ratio but had a tendency to produce sterility and abortion. This opinion 

 was confirmed by an examination of the ovarian tissue of the treated rabbits. 



Another sex-limited character in fowls, A. H. Sturtevant (Science, n. ser., 

 S3 (1911), No. 844, PP- 337, 838). — A preliminary report of experiments in cross- 

 ing Columbian Wyaudottes and Brown Leghorns. 



An experiment dealing with sex-linkage in fowls, A. H. Sturtevant 

 {Jour. Expt. Zool., 12 (1912), No. 4, pp. 499-518, figs. 4)-— A continuation of 

 work noted above, and summarized as follows : 



" There is a sex-linked factor carried by the Columbian Wyandotte — an 

 inhibitor for red in the plumage. This breed probably also carries another sex- 

 linked factor, an inhibitor for red in the neck. It apparently carries a pattern 

 factor inhibiting the breast color, and, in the female, the stippled back of the 

 Brown Leghorn. The silver-gray color is probably epistatic to the Jungle fowl 

 or brown color. The White Wyandotte is a silver-laced breed with a color 

 producer dropped out. 



" An attempt is made to explain three sets of phenomena, in fowls, in 

 canaries, and in Aglia tau respectively, as cases of partial sex-linkage. Using 

 this explanation, it is argued that the sex formula for birds and Lepidoptera 

 is probably: $, MM, FF; 9, Mw, FF. The case of the dwarf guinea pig is 

 explained as perhaps representing partial sex-linkage in a form where the male 

 is heterozygous for sex." 



A bibliography is appended. 



"Arch. Fisiol., 1 (1904), p. 604. 



