ANIMAL PRODUCTION. 73 



The eflFect of variations in the method employed for the artificial digestion 

 of proteid materials, G. Berju {Dent. Med. ZUj., 22 [1901), jip. 567, 568; ab.s. in 

 Ztxciir. Uxterxiu-h. Xnlir. v. GenussmtL, 5 (1902), No. 6, p. 275). — Experimental data 

 are rej>orte<l. 



Some observations on the metabolism of protein, M. Gkuber {Ztschr. Biol., 

 42 {1901), pp. 407-427, chjws. 3). — A number of the principles of metabolism are dis- 

 cussed at length in connection with the author's experiments. The author believes 

 that fat is formed from protein and cites experiments in proof of this contention. 

 Tlie possibility of increasing the size of the organs of the body by any system of diet 

 is also discussed, the author believing that this is only possible within the most nar- 

 row limits. The small gains or losses of nitrogen which are observed in metabolism 

 experiments are discussed in detail and are believed by the author to depend upon a 

 retention of protein or an increased metabolism of this nutrient, as the case may be. 

 The protection of protein by different materials is also discussed. 



Heat of combustion and physiological nutritive value of foods. I, Meat, 

 J. Frentzel and ]\I. Schkeuek [Arch. Anat. u. Physiol., Fliysiol. Aht., 1901, pp. 

 284-298; abs. In Ztschr. Untersuch. Nahr. u. GenussmtL, 5 {1902), No. 6, pp.266). — 

 Exj)eriments with a dog are reported which led to the conclusion that 74.84 percent 

 of the energy supjilied in meat was rendered availal)le l)y the body. 



An experimental contribution to the question of the physiological protein 

 minimum, ]\I. ("kemer and 31. Henderson [Ztxclir. Uiol., 42 {1901), pp. 612-618). — 

 Experiments with a dog are reported, in which the metabolism of nitrogen was 

 studied. 



Concerning the cause of increased proteid metabolism during fasting, F. N. 

 ScHULZ {^Ztschr. Biol., 41 {1^01), No. 3, pp. 368-377).— A controversial article. 



The influence of body fat in fasting animals, E. Yoit {Ztschr. Biol., 41 {1901), 

 No. 4, pp- 502-549, dgms. 5). — A number of experiments, some of which were made 

 by the author, with different animals, are quoted and discussed in detail. Accord- 

 ing to the author, proteid cleavage in a fasting animal is markedly influenced by the 

 fat content of the body. If a large amount of fat is present, the metabolism of pro- 

 tein is not increased at the beginning of the fasting jieriod. However, as soon as the 

 fat is diminished to a certain amount the cleavage of protein is relatively increased. 

 Apparently the relation between the body fat content and the cleavage of i>rotein is 

 the same with different classes of animals, so that it is possible by means of the 

 amount of proteid cleavage to estimate the amount of fat present. The effect of body 

 fat up.on the amount of proteid cleavage is dependent upon the relation between the 

 amount of fat in circulation and the amount present in the fat reservoirs of the body. 

 The relation between death due to fasting and the fat content of the body is also 

 discussed. 



Concerning the cause of the increased cleavage of protein during fasting, 

 E. VoiT (Ztschr. Biol., 41 [1901), No. 4, ]>p. 550-571).— \ further discussion of the 

 subject noted above. Kespiratory quotient experiments are reported. These tests 

 also indicate that the cleavage of protein is dependent upon the amount of fat present 

 in the body. 



The formation of fat from carbohydrates, K. B. Lehmann and E. Voir {Ztschr. 

 Biol., 4^ {1901), pp. '619-671). — A large number of experiments are reported which, 

 the authors believe, show that fat may be formed from carbohydrates. In some of 

 the experiments food, urine, and feces were taken into account; in others the res- 

 piratory products were also studied. 



The utilization of rhamnose by the animal body and the related question 

 of the physiological value of carbohydrates, M. C'remer (Z/.sr//c. Hiol.,42 {1901), 

 pp. 4~S-467). — The work of earlier investigators is reviewed at some length and exper- 



