268 EXPERIMENT STATION RECOED. 



They reflect changes in the coiulition of nutrition of the mother, at a critical 

 period in the formation of the unborn young, and suggest the possibility of 

 affecting the fertility of sheep and controlling the sex of their offspring by 

 suitable feeding for a short period of time before and after the time of mating." 



Feeling that the absolute number of ewes involved was too small to give 

 certainty to the averages, further observations were made and a table pre- 

 pared combining all the records. The weight of over 100 mothers of male 

 lambs, taken in the autumn preceding birth of lambs was for September 30, 

 90.3 lbs. ; October 31, 96.2 ; November 30, 95.6 ; and December 31, 94 lbs. ; and 

 for mothers of female lambs 91.2, 96.4, 95.2, and 94 lbs., respectively. Here it 

 Is shown that the average weights were practically the same and would evi- 

 dently discountenance former conclusions. It is thought that this inconsis- 

 tency may be accounted for by the fact that the male-bearing ewes increased 

 in weight at n gi'eater rate than the female-bearing ewes during the month of 

 October. They started lower and reached the same point by the end of the 

 month. A marked difference was found to exist between the weight curves 

 for the two clas.ses of ewes, twin-bearing and single-bearing. However, the 

 author hesitates to draw a conclusion from these observations. 



Annual report, 1912: Sheep division, A. G. Michaelian (Union So. Africa 

 Dept. Affi: Rpt. r.)12-13, pp. 71-135). — A statistical report of the sheep and goat 

 industry in the Union of South Africa. 



Wool carding- and combing, A. F. Barker and E. Priestley {New York, 

 London, Toronto, and Melbourne, 1912, pp. XII+264, pis. 45. figs. 34).— The 

 chapters included in this book are on wool and hair-producing animals; sheep 

 breeding and Mendel ism ; wools, hair, and the manufactured materials; com- 

 merce in wools and hairs ; wool classing and sorting ; the physical and chemical 

 properties of wools, hairs, etc.; wool steeping, scouring, and drying; types of 

 yarns generally considered; the preparation of long wools (English, cross-bred 

 wools, and Merino wool for combing) ; and combing, recombing. and finishing. 



A chemical study of the nutrition of swine, E. B. Forbes, F. M. Beegle, 

 C. M. Fritz, and J. E. Mensching (Ohio Sta. Bui. 271 (1914), PP- 225-261, figs. 

 3). — Five pigs from the same litter were used in a metabolism experiment 

 involving eight 10-day periods, separated by 7-day intervals. The feeds used were 

 corn alone in two periods; com supplemented by soy beans, linseed-oil meal, 

 wheat middlings, meat meal, and skim milk; and a ration of rice polish and 

 wheat bran. 



It was demonstrated that as sources of calcium for growing swine, corn, 

 wheat middlings, linseed-oil meal, soy beans, wheat bran, and rice polish are 

 imsatisfactory and will not maintain normal growth of bone. From 9 to 10 

 times as much calcium was retained fx'om rations containing milk and meat 

 ■meal as from the best one of the grain rations, which emphasizes the need of 

 supplying those feeds rich in calcium, such as pasture and forage crops, espe- 

 cially the leguminous plants. 



Corn was deficient in calcium, phosphorus, and nitrogen. Phosphorus was 

 stored on all the rations but was insufScient for maximum growth in the ration 

 of corn alone. In the ration of rice polish and wheat bi'an. which contained 

 12 times as much magnesium as calcium, the excess of magnesium appeared 

 to cause a loss of calcium from the animal. Although the remaining rations 

 contained an excess of acid over basic mineral elements, it did not affect cal- 

 cium retention. 



The ammonia of the urine was found to increase with the excess mineral 

 acidity and the total pi-otein of the ration. 



One part of sodium chlorid to 256 parts of other feeds seemed to be more 

 than sufficient for growing swine. It was found that the balances of sodium 



