ANIMAL PRODUCTION. 765 



II, Intraracial correlation in swine (pp. 31, 32). — Biometrical methods are 

 applied to statistics collected by E. N. Wentwortli in 1913 on the correlation 

 between number of mammse and size of litter in Duroc Jersey swine (E. S. R., 

 29, p. 470). It is shown that "there are approximately 2.5 more mammae in 

 the dam, on the average, than number of young in the litter iu these swine. 

 This is a slightly larger ' factor of safety ' than is found interracially. The 

 intraracial correlation between these variables in swine is not only absolutely 

 low but is relatively much lower than the interracial correlation. Again it is 

 not apparent here that natural selection has operated in the expected manner. 



" Intraracially, just as interracially, size of litter is relatively a more variable 

 character than number of mammae in the dam. There is, as would be expected, 

 a very considerable reduction in variability, in respect of both characters, in 

 the single species (intraracial) as compared with the composite group of 90 

 different species (interracial)." 



A note on sex determination, G. H. Parker (Science, n. ser., 39 (1914), ^o. 

 991, pp. 215, 216). — In collecting data to show the relation of the size of litters 

 lo the number of nipples in swine, observations were made on the position that 

 the young pigs occupied in the uterus and their sex, and it was therefore pos- 

 sible to ma lie a comparison of the products of one ovary with those of the 

 other. A tabulation was made of the frequency of occurrence of pairs of unborn 

 pigs of various combinations of sex at the division of the horns of the uterus 

 next the right ovary and next the left ovary, the observations extending over 

 2,600 pairs of pigs. In all three positions the frequencies of the pairs were 

 approximately in the ratio of 25 per cent males: 25 per cent females: 50 per 

 cent males and females, showing that in the pig the ovaries exert no influence 

 on the sex of the offspring by virtue of their position in the maternal body. 



On the atavistic long' stripe of the new-born young of certain breeds of 

 domestic swine, E. A. Goeldi (9. Cony. Inteniat. ZooL, 1913, pp. 369, 370). — 

 The author commenis on a phenomenon of the atavism of coloration, a long 

 stripe, sometimes found iu the young of some of our domestic breeds of swine, 

 as the Berkshire and Yorkshire, and which evidently traces back to the early 

 types of wild swine. 



Eudimentary parthenogenesis in the golden pheasant, Lecaillon (Compt. 

 Rend. Acad. Sci. [Paris], 158 (1914), A'o. 1, pp. 55-57; ahs. in Internat. Inst, 

 igr. [Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 5 (1914), ^'o. 4, pp. 502, 

 503). — The author made a study of the unfertilized eggs from a golden pheasant 

 {('Jhnjsolophtis pictus) to determine whether rudimentary parthenogenesis ap- 

 plies to this species as it does in the case of the hen. 



it was found that the eicatricula shows blastomeres of varying size and that 

 the.se are composed of cytoplasm and deutoplasm and contain normal nuclei. 

 The degeneration of the blastomeres is often characterized by hypertrophy of 

 the nuclei, which form numerous fresh nuclei of various sizes by budding. It 

 is concluded from these observations that unfertilized eggs always show a tend- 

 ency to develop like fertilized ones. 



The distribution of creatin in the bodies of mammals, J. C. Beker (Hoppe- 

 Seylefs Ztschr. Physiol. Chem., 87 (1913), No. 1, pp. 2i-37).— Analyses made to 

 determine the creatin and creatinin content of the organs of the cow, goat, pig, 

 rabbit, and dog showed the largest amount of creatinin present in the volun- 

 tary muscles and the least in the thymus gland. The fetus shows a low creatin 

 content. The creatinin content increases in animals in advanced pregnancy. 



The digestibility of cattle foods, J. B. Lindsey and P. H. Smith (Massachu- 

 setts Sta. Bui. 152 (1914), pp. 79-120).— This bulletin contains the results of 47 

 single digestion experiments with a variety of cattle feeds. The basal ration 

 consisted of hay, corn, and gluten. The experiments were conducted with sheep. 



