ANIMAL PEODUCTION. 669 



The partial transformation of food fat into mannites by peptic and pan- 

 creatic digestion in vitro, fl Gautrelet {Gompt. Rend. Acad. Sci. [Paris], lJf9 

 (1009). No. 24, PP- 1150, 1151). — From his experiments the author concludes 

 that in both sorts of artificial digestion mannites were formed from fat. 



On the nature of the so-called fat of tissues and organs, H. MacLean and 

 O. T. Williams {Bio-Chem. Jour., Jf {1909), No. 10, pp. 455-.',61).— The high 

 saponification number of the fat obtained, by thorough extraction with alcohol 

 aud ether, from the blood, organs, and tissue of dogs showed that the material 

 could not be composed to any extent of ordinary fat. According to the 

 authors, " the high saponification values were found to be caused by combina- 

 tion of part of the sodium with phosphoric acid and glycero-phosphoric acid 

 liberated during the process of saponification. 



"Every organ and tissue naturally contains more or less neutral fat in the 

 interstices of its substance; but though it would seem that the preponderating 

 portion of the 'fat' combined with protein in the bioplasm as masked fat is 

 present as phosphatid, in addition some of the phosphatid is present in free 

 form, perhaps as a phase in its passage to combination ; free phosphatids 

 would, on this view, constitute preliminary substances which subsequently 

 pass on to actual combination in the tissues. In a normal organ, therefore, 

 the less microscopical evidence there is of fat, the less neutral fat is actually 

 present; while the combined fat — a phosphatid — seems to represent one of 

 those steps in that synthetical elaboration of fats which appears to be a nec- 

 essary prelude to actual assimilation. It is not improbable that phosphatids 

 represent a necessary step in the elaboration of fatty substances destined 

 ultimately to undergo actual assimilation into living matter. That such sub- 

 stances are essential for the vital processes seems indicated by their presence 

 in all living cells hitherto investigated; it can not be doubted that one of 

 the steps which ordinary fat undergoes in the cell is a transformation into 

 l)hosphatid, and probal)]y in these bodies the desaturation of the fatty acid 

 radicle is brought about. Whether this elaboration is necessary for the ulti- 

 mate oxidation of all fats, or whether we have here wholly or in part a 

 process somewhat analogous to the endogenous metabolism of protein, can 

 as yet be but conjecture. The fact, however, that phosphatids contain [trac- 

 tically all the constituents ... of nucleo-i>roteins, is not without significance, 

 and it is not unlikely . . . that they may be the source of the cell nucleo- 

 proteins." 



Experiments on the amount and character of fat in pig liver were also 

 briefly reported. From the data obtained the author concludes that appar- 

 ently " the essential fat of the liver, and probably of certain other organs, is 

 really phosphatid, and under certain circumstances, if care be taken to avoid 

 disintegration during the process of extraction, it may be practically the only 

 one found in any appreciable amount in the combined part of the ' fat.' " 



Concerning the partition of nitrogen in the urine of infants, H. Vogt 

 (Monatsschr. KinderhcUk., 8' (1909), No. 2-3; ahs. in Zenthh Gesam. Physiol, 

 u. Path. Stoffwcchsels, n. ser., 4 (1909), No. 19, p. 761).— The author concludes 

 that in the case of healthy infants, as with adults, the partition of nitrogen in 

 the urine is rather constant, provided there are no abnormalities in the compo- 

 sition of the food. His other conclusions have to do with pathological conditions. 



ANIMAL PEODUCTION. 



Forage plants of Uruguay and their value as feeding stuffs for cattle, 

 J. ScHROEDER (Rci\ Sccc. Agroti. Univ. Montevideo, 1907, No. 2, pp. 86-103; 1908, 

 No. 3, pp. 119-llfl)- — Analyses of alfalfa, clovers, grasses, and other forage 

 plants of Uruguay are reported and their value for feeding purposes discussed. 



