ANIMAL PRODUCTION. 267 



markedly the size aud strength of the newborn pigs. The meat-meal ration gave 

 somewhat better results than where a vegetable protein supplement such as lin- 

 seed-oil meal was allowed. It was noted that both meat meal and oil meal in- 

 creased the coat as well as the color of the skin. The meat meal produced a 

 larger bone than oil meal, and both of these surpassed corn alone. 



Attention is called to the small number of offspring per ewe in the corn 

 silage lot, which contributes largely to the increased size of the young. Where 

 silage was fed in addition to clover the vigor and size of the offspring was in- 

 creased, whereas alfalfa as compared with clover, being richer in protein and 

 ash than clover, produced the strongest and largest lambs, even though there 

 were more of them. It is stated that more recent experiments have shown quite 

 clearly that cotton-seed meal added to corn and corn silage increases the 

 strength as well as the size of the offspring. 



On the variation in the growth of mammalian tissue in vitro according to 

 the age of the animal, A. J. Walton (Proc. Roy. Soc. [London], Ser. B, 88 

 {1915), No. B 606, pp. 476-482, pi. i).— The author concludes from his investi- 

 gations that "growth of tissues in vitro affords a valuable means of investiga- 

 tion as to the effects of age upon growth. The tissues of young animals grow 

 more rapidly and vigorously than those of adult animals. The plasma of young 

 animals is a much less suitable medium for the growth of tissue in vitro than 

 the plasma of old animals. The uusuitability of the plasma of young animals 

 as a medium is probably due to the presence of an increased amount of some 

 inhibiting substance." 



The English rabbit and the question of Mendelian unit-character con- 

 stancy, W. E. Castle and P. B. Hadley (Proc. Nat. Acad. Sci., 1 {1915), No. 1, 

 pp. 39-42, figs. 6). — In breeding experiments with rabbits the authors disprove 

 the idea of unit-character constancy, or " gametic purity." It is said that " if 

 crossing is likely to produce considerable changes in the characters which it is 

 desired to combine in a new race, it is evident that Mendelian crosses must be 

 used judiciously and with caution by the practical breeder," and that " if unit 

 characters are not constant, selection reacquires much of the importance which 

 it was regarded as possessing in Darwin's scheme of evolution, an importance 

 which many have recently denied to it. 



Breeding of farm animals, M. W. Haepee (New York: Orange Judd Co., 

 1914, PP- XyiI+335, figs. 104). — This is a general treatise on animal breeding 

 designed for the farmer, breeder, and student. It discusses the fundamental 

 principles underlying animal breeding such as development, selection, variation, 

 and heredity, together with the more practical phases of the work. An appen- 

 dix contains tables giving data as to breeds and breeders' associations. 



The jack bean (Canavalia ensiformis), F. Baenstein {Landio. Vers. Stat., 85 

 {1914), No. 1-2, pp. 113-122). — The composition of the jack bean (C. ensiformis) 

 is reported as water 13.26 per cent, protein 31.51, fat 2.18, nitrogen-free extract 

 41.99, fiber 8.59. and ash 2.47. The coefficients of digestibility as determined 

 in a 4-week test with sheep are given as dry matter 87.5 per cent, organic mat- 

 ter 88.6, protein 80.5, fat 72.1, nitrogen-free extract 99.1, and fiber 72.9. The 

 starch value is estimated to be 63.7, with 18.69 per cent of digestible protein, 

 making it somewhat lower in nutritive value than the common field bean. The 

 sheep were fed 0.44 lb. of crushed beans per day without apparent injurious 

 effects. 



Beet residues for farm stock, J. B. Lindsey (Massachusetts Sta. Circ. 48 

 {1914), pp. 7). — ^A general discussion of the feeding value of dried beet pulp, 



