ANIMAL PRODUCTION. 171 



:is a iiiitrleiit and sonietiuu s daii^^eroiis. Tho experiments were made wltli dogs. 



The biolog-ical significance of lecithin, I, W. Glikin (Biochcin. Ztschr., 7 

 (1907), Xo. 3. pp. .2S6-.298). — A comparison of new-born mammals (dogs, rabbits, 

 and cats) witli birds featberless wben newly liatcbed showed that there were 

 close resemblances and indicated that helplessness at birth implies a high 

 lecithin content. 



The role of osmotic pressure in the phenomena of animal life, J. Demoor 

 ET AL. (Mem. Acad. Roy. Belg., 2. ser., 2 (1907), pp. 112; ahs. in Biochem. CentU., 

 7 (1908), No. 1, pp. 8, 9). — In the Investigations reported salt solutions of dif- 

 ferent concentration were passed through different organs and the changes in 

 volume and rate of passage were noted. The special apparatus used in these 

 experiments is described. 



ANIMAL PRODUCTION. 



Experiments on the digestibility of prickly pear by cattle, R. F. Hare 

 (f. X. Dcpt. Agr.. Bur. Animal Indus. Bui. 106, pp. SS, pi. 1. fig. 1). — Using 

 steers as subjects, tive experiments were made to determine the digestibility of 

 prickly pear of different sorts alone and fed with alfalfa and cotton-seed meal 

 in comparison with alfalfa hay alone. The income and outgo of nitrogen was 

 also studied. 



According to the author's conclusions — 



"The average digestibility of the nutrients of prickly pear as determined in 

 the first experiment where Opuntia lindheimeri was used were : Dry matter, 

 U5.8G per cent ; ash, 33.G8 per cent ; protein, 57.47 per cent ; fat, 68.38 per cent ; 

 crude fiber, 41.32 per cent ; nitrogen-free extract, 81.78 per cent. 



"In the second experiment where the variety O. Icevis? was used the coeffi- 

 cients of digestion were: I>ry matter, 63.96 per cent; ash, 35.81 per cent; pro- 

 tein. 40.87 per cent; fat, 69.02 per cent; crude fiber, 53.99 per cent; nitrogen-free 

 extract 78.95 per cent. 



" In general these results would perhaps show a somewhat low coefficient for 

 protein, a decidedly low coefficient for ash, but a very high coefficient for the 

 nitrogen-free extract. The total digestible nutrients are about equal to those of 

 immature green corn fodder. 



" Our experiments seem to show that when prickly pear is fed with cured 

 fodders or grains the digestibility of both is increased. For this reason prickly 

 pear has a greater food value than is shown by Its analysis and digestion 

 coefficients. 



" The nutritive ratio, i. e., the ratio of proteids to carbohydrates, is very wide 

 for this feed, and in feeding it to all classes of animals, for whatever purpose, 

 much better results should be obtained when it is fed with some substance of a 

 high protein content. 



" While the digestibility of the ash was apparently small, as noted above, yet 

 the large amount of ash contained in these plants caused more ash to be assimi- 

 lated from a ration equivalent to 15 lbs. of dry matter than is ordinarily assimi- 

 lated from an equal ration of alfalfa, which has a higher coefficient of digestion 

 for its ash. 



" The steers seldom drank water when fed prickly pear alone. In fact, in 

 feeding a ration of 100 lbs. of this feed per day the animals obtained from the 

 feed over 8 gal. of water, which is more than was usually drunk by them when 

 fed cured fodders alone. 



" While no digestion experiments were made with any of the cacti other than 

 prickly pear, the digestion coefficients of the latter could probably be safely 



57401— Xo. 2—08 6 



