136 Physiologie der Zellen, Gewebe und Organe. 



in order to remove a portion of the repired carbon dioxide and prevent asphyxia- 

 tion of the embryo. The normal embryo is able to withstand a wide Variation 

 of carbon dioxide during incubation. It is practically impossible to remove all 

 of this gas from the egg Chamber without serious results from excessive eva- 

 poration. Where the Ventilation was increased and the carbon dioxide did not 

 exceed 30 parts in 10000 (a low maximum) no marked reduction in the per- 

 centage hatch was found. Good results were obtained in all cases when the 

 carbon dioxide did not exceed 60 parts in 10 000 which approximates the amount 

 found in natural incubation. The effect of carbon dioxide is slight until a maximum 

 of 150 parts is reached, as the amount rises above this point there is a marked 

 decrease in the number of chickens hatched. Pearl. 



339) Muniford, H. W„ Grindley, H. 8., Hall, L. D. and Einmett, A. D., 



A Study of the Digestibility of Rations for Steers with Special 

 Reference to the Influence of the Character and. the Amount of 

 Feed Consumed. In: 111. Agr. Expt. Sta. Bull. No. 172, S. 235—278, June 

 1914. 



This bulletin, which is one of a series, deals with the effect upon the coef- 

 ficients of digestibility (l) of variations in the proportions of roughage and con- 

 centrates in the ration, (2) of the Substitution of a nitrogenous concentrate for 

 a part of the grain of a ration of roughage and grain in the ration of 1 : 5, and 

 (3) of variations in the amount of feed consumed from maintenance rations to 

 füll feed. The cause of differences in digestibility induced by differences in the 

 amounts of feed consumed seems to be the proportion of hay in the ration. 

 Apparently, the essential point of difference caused by the larger proportion of 

 hay is in the content of crude fiber. Hence, it may be said that differences in 

 the amounts of feed consumed influence the digestibility only when the quantity 

 of crude fiber in the ration is relatively large. Pearl. 



340) Nelson, S. B., A Report of the Results of the Continued Injec- 

 tions of Tuberculin Upon Tubercular Cattle. In: Wash. Agr. Exp. Sta. 

 Bull. No. 114, S. 1—15, Oct. 1914. 



This paper deals with the physiological effect of repeated injections of tu- 

 berculin and shows that the injection into tubercular cattle of large monthly or 

 small weekly doses of tuberculin does not apparently have therapeutic value. 

 The injection of constantly increased daily or weekly doses of tuberculin appa- 

 rently does have therapeutic value. The evening temperature is usually higher 

 than the morning temperature in tubercular cows. The oftener tuberculin in- 

 jections are made into tubercular cattle, the sooner the temperature reaction 

 begins and the sooner the zenith is reached. Pearl. 



341) Einmet, A. D., Grindley, H. S., Joseph, W. E. and Williams, R. H., 



A Study of the Development of Growing Pigs with Special Refe- 

 rence to the Influence of the Quantity of Protein Consumed. In: 

 111. Agr. Expt. Sta. Bull. No. 168, S. 85 — 135, March 1914. 



A daily ration of ground corn, blood mean, and an ample amount of calcium 

 phosphate, containing only 0,32 pound of digestible protein, and yielding only 

 3,79 therms of metabolizable energy per 100 pounds live weight, is not suffi- 

 cient for the normal nutrition of young, growing pigs. It is impossible to ac- 

 count for this fact definitely, but it is probable that the ration either does not 

 contain enough of the right kind of protein or does not yield enough energy. 

 Daily rations of ground corn, blood meal, and an ample amount of calcium phos- 



