ANIMAL PEODUCTTON. 773 



A review of the literature ou tliis topic, with suggestions as to wlieu inbreeding 

 can be practiced with safety. 



A literary note on Mendel's law, W. AV. Stockbebger (Amer. Nat., -}6' {1912), 

 No. ').'fS. pp. 151-151). — This is a synoptic statement of the fundamental prin- 

 ciples of Mendel's work, with many biblio2;raphical notes. 



Tables of statistical error, R. Ross and W. Stott {Ami. Trop. Med. and 

 Par., 5 (IDll), No. 3, pp. 3'i7-369). — This contains tables specially constructed 

 for practical work in biology, eugenics, pathology, and sanitary science. Ex- 

 amples are given showing how to find the percentage of statistical error in pro- 

 portionately small samples, propoi'tionatelj^ large samples, and in things of one 

 class. 



The law of vast numbers (Amer. Breeders Mag., 2 {1911), No. 4, pp. SOS- 

 307). — An editorial containing suggestions for a method of procedure in breed- 

 ing experiments. Reference is made to circuit breeding methods in Minnesota 

 and North Dakota, wherein a selection of breeding animals can be made from 

 a much larger number than is possible among individual breeders. 



The determination of sex and Mendel's law, F. E. Peck {Hoard's Dairy- 

 man., .'t3 {1912), No. S, p. 309, fiff. 1). — Mendel's law as applied to sex determi- 

 nation is discussed and illustrated by diagram. 



New arguments in favor of the action of the suprarenal glands in the 

 determination of sex, R. Robinson {Compt. Rend. Acad. Hci. [Paris], 153 

 (1911), No. 21, pp. 1026, 1027). — From chemical observations the author thinks 

 that pathological conditions of the suprarenal capsules in females interfere with 

 the normal functioning of the ovaries, and that sex is closely associated with 

 the activity of these glands. 



The problem of sex determination in Dinophilus gyrociliatus. — I, The 

 sexual cycle, C. Shearer (Quart. Jour. Micros. Sci. [London], n. ser., 57 

 (1912), No. 227, pp. 329-371, pis. 5, figs. 5).— A study of the factors in sex deter- 

 mination in fertilized and in parthenogenetic eggs. The details of fertilization 

 and oogenesis are given, and it is concluded that the presence of large eggs, 

 which invariably give rise to females, seems to be due to fertilization, the unfer- 

 tilized eggs being smaller and giving origin to the males. 



Sex determination in daphnids, R. Woltereck (Internat. Rev. Gesam. 

 Hijdrohiol. lo. Hijdrog., // (1911), No. 1-2, pp. 91-128. figs. 6; ahs. in Jour. Roy. 

 Micros. Soc. 1911, No. 6, pp. 757, 758). — In continuation of earlier work 

 (B. S. R., 25, p. 171) the author concludes that external conditions may some- 

 times have a distinct influence on the sex of the developed ovarian ova, as 

 well as on the ova to be subsequently formed. The view is expressed that in 

 the ovum are competing sex substances, one of which becomes active as the 

 egg matures, while tlie other remains latent. This inhibition may occur at 2 

 different periods, one shortly before the ovum leaves the ovary, and the other 

 much earlier, as in the undifferentiated germ layer of the ovary, in the gonail 

 primordium of the winter egg. or in the ripening female egg. External influ- 

 ences act only when the internal conditions of maturation and activation are 

 approximately the same for the 2 sex substances. 



" If we adopt the author's suggestion of applying the ideas of the ferment 

 and antigen theory to these substances and processes, we can suppose that the 

 alternating appearance and suppression of inhibiting substances ('paraly- 

 sators'i, or of activating substances ('activators'), are the I'eal causes of the 

 periodicity of sex determination. The sex substances themselves may be con- 

 sidered as somewhat like pro-ferments (if latent), and ferments (if 

 activated)." 



The determination of sex in the human species, Mrs. D. McConnel (Cal. 

 Htate Jour. Med., 9 (1911), No. 9, pp. 37(?-^72).— Experience and observations 



