ANIMAL PRODUCTION. 269 



isud chlorin were largely controlletl by the amount of water drunk. There wi.s 

 ;in extensive metabolism of sodium apart from chlorln. The feces may contain 

 an abundance of sodium but are nearly free from chlorin. 



Magnesium tends to deflect the phosphorus excrption from urine to feces, 

 and excessive phosphorus content of the ration limits the absorption of mag- 

 lu'sium. With an intake of 2.17 gm. of magnesium and .".4 gm. of phosphorus 

 there was a storage of magnesium, but with an intake of 9.28 gm. magnesium 

 and 20.17 gm. phosiihorus there was a loss of magnesium, combined with phos- 

 phorus, through the feces. 



The potassium of these rations was more than sulUcieut in all cases. With 

 the maximum intake, however, on the ration of wheat bran and rice polish, 

 there was a loss of potassium, apparently through an excretion of previously 

 stored excess. The urinary i)otassium varied inversely as the retention. 



Nitrogen and sulphur balances were all positive. Sodium. ]K>tassium, sul- 

 1-hur. and chlorin were excreted in larger proportion in the urine than in the 

 feces, while calcium, magnesium, and phosphorus left the bodj' more largely in 

 the feces. 



The digestibility of the starch of corn was increased by the feeding with it 

 of soy beans, tankage, and milk. Tankage and milk also increased the digesti- 

 bility of the fat, and decreasetl the digestibility of the crude fiber of corn. Crea- 

 tinin excretion in the urine was shown to l)e entirely independent of the feed, 

 and to vary among the several individuals in the same order as live weight and 

 weight dressed carcass, flesh, bone, and blood. 



The metabolism crates used iu the experiments are briefly described. 



Pork that is made at home, P. F. Tbowbriuck {('ouutry Gent., 79 (1914), 

 No. 7, pp. 298, 299. figs. 14)- — An account of the slaughtering, cutting up, and 

 curing of j)ork for homo jiurposes. 



Productive horse husbandry, C. W. (Jay {Philadelphia and London, 191.'f. 

 pp. .\V-{-S31, pi. 1, figs. nS). — This book is a comitrehensive treatise on th;> 

 structure and function of the horse, the types and breeds of horses, the prin- 

 ciples of horse breeding, the feed, care, and management of the liorse, stables, 

 equitation, and markets and shows. 



Weights and measurements of horses, H. W. Wynn (Live Stock Jour. 

 [London], 79 (1914), No. 2082, p. 199). — There are given the average weights 

 and measurements of 370 horses, representing the cavah-y, mounted infantry, 

 artillery, bus, li^ht vanner, and hunter classes. 



Origin of Argentina wild horses, W. D. Matthew (Nature [London], 92 

 [1914), No. 2311, p. 661). — The author presents evidence to show that the theory 

 that the existing wild horses of South America are descended either wholly or 

 partly from any surviving native stock is erroneous. He points out that the 

 infertility of crosses between zebras or asses and domestic horses is based upon 

 a separation dating back at least to the late Pliocene age, and since the species 

 native to Argentina, if they continued to exist down to modern times, would 

 have evolved in complete isolation from any northern species since the early 

 Pleistocene, they should be equally infertile when crossed with the domestic 

 stock. However, this is not the case. Assuming that the native horses may 

 have survived in Argentina until the time of the Spanish settlement, the stock 

 would not be able to interbreed with domestic stock and would remain separate 

 and unmixed until exterminated. 



The great producing brood-mare families, J. C. McCoy (Am£r. Horse 

 Breeder, 32 (1914), No. 9, p. 129, figs. 3).— After commenting on the ancestry 

 and attributes of several of our principal brood-mare families the author points 

 out that to-day " our best results are coming from blending several crosses of 

 the top of the Hambletonian family with several crosses of the great brood- 



