ANIMAL PRODUCTION. 673 



ments were made with fasting swine to determine the minimum energy trans- 

 formation for the maintenance of life. 



According to these, in the case of lean growing swine, the transformation of 

 energy was least at from 20 to 23° C, which is therefore the critical tempera- 

 ture. In the case of fattened animals the critical temperature may be about 

 17°. The transformation of energy determined at the critical temperature 

 represents the minimum energy elimination of the swine, which according to 

 the experiments averaged for fat swine 19.6 calories per kilogram, or 1,060 

 calories per square meter of body surface; for lean swine, 27.2 calories per 

 kilogram or 1,100 calories per square meter. According to these figures the 

 energj' elimination i>er unit of body surface is independent of the fat content 

 of the body. 



On ovariotomy in sows, with observations on the mammary glands and 

 internal g-enital organs, II, K. J. J. Mackenzie and F. H. A. Marshall (Jour. 

 Agr. Sci. [England], 5 (1913), No. 4, pp. 418-^23, pi. i).— Continuing studies 

 previously noted (E. S. R., 27, p. 875) it was found that black pigment is very 

 frequently, but not invariably, present in the mammary tissue of Large Black, 

 Berkshire, and other dark-colored sows. It is thought that by breeding from 

 individuals in which this pigment is absent a strain may be built up of increased 

 commercial value. It was further found that imperfect spaying, in which 

 one, or a part of one, ovary is left behind, accounts for the frequent occurrence 

 of spayed sows behaving as though they were " open." 



Studies in comparative digestive physiology. — VI, On the course of drink- 

 ing water in the stomach and the intestine of the horse, A. Scheunert 

 iPfluger\s Arch. Physiol., 151 (1913), No. 7-10. pp. 896-406) .—This is a con- 

 tinuation of studies previously reported (E. S. R., 28, p. 367). In this are 

 given the percentages of water content in the forestomach, the fundus, and the 

 pylorus portions of the stomach of the horse, when fed various quantities 

 and proportions of hay, oats, and chopped straw. A study was also made of 

 (he course of and time required for the transport of water through the intestine. 



[Studies on the normal intestinal flora of the horse], Anna Hopffe 

 (Ztschr. Infektionskrank. u. Hyg. Haustiere, I4 {1913), Nos. 4-5, pp. 307-315; 

 6, pp. 383-404)- — Studies are reported of the normal intestinal flora found in 

 the forestomach, fundus, pylorus, cecum, doudenum, colon, ileum, and rectum of 

 the horse at periods immediately after, f , 1^, and 3 hours after feeding, together 

 with the degree of acidity or alkalinity detected. 



Did the horse exist in America before this continent was discovered by 

 Europeans? E. Trouessart (Sci. Amer. Sup., 76 (1913), No. 1981, p. 387). — 

 This article has been previously reported from the original source (E. S. R., 

 30, p. 174). 



Biological searchlight on race horse breeding. — VI, The heredity of blood- 

 vessel breaking in the Thoroughbred, J. B. Robertson (Bloodstock Breeders' 

 Rev., 2 (1913), No. 4, pp. 265-281).— In this article (E. S. R., 29, p. 773) the 

 author traces the early history of blood-vessel breaking, and presents evidence 

 to show the hereditability of this character. It is shown that while only one 

 runner out of every 400 each year, on the average, breaks a blood vessel, the 

 affected individuals have a close common bond and are readily referable to 

 common sources. Herod, foaled in 1758, is given as the prime, if not the sole, 

 source of blood-vessel breaking in the English Thoroughbred. This phenomenon 

 behaves as a recessive character, being carried in a latent form by either sex. 

 The author points out that while ordinarily "a true recessive character, such 

 as chestnut coat-color, only becomes patent in the individual when a determin- 

 ing factor for it has been inherited from both parents ... in certain charac- 



