172 



MANUAL OF CATTLE-FEEBING. 



tairied m its dry substance the enormous amount of 76.8 

 per cent, of fat. 



If a doubt still remained as to tlie formation of fat from 

 albuminoids, it must disappear on a consideration of the 

 results which have been obtained on healthy animals with 

 an entirely normal food. For example, the eggs of ordi- 

 nary flies have been allowed to develop on pme blood and 

 from seven to eleven times as much fat found in the larva3 

 as was originally contained in eggs and blood together, 

 although the animals had not consumed nearly all the 

 blood ; the excess of fat could only have come from the 

 albumuioids of the food. 



Yet more important, however, are the numerous experi- 

 ments made by feeding doge on large quantities of pure 

 (fat-free) meat. 



The three following experiments by Voit & Pettenko- 

 fer"^ may serve as an example. In these experiments the 

 respiration apparatus was used, and hence the excretion of 

 carbon, as well as of nitrogen, could be determined : 





Fifth day of feeding 



with i,m 



grms. meat. 



Second day of feed- 

 ing with 2,500 

 grms. meat. 



First day of feeding 

 with 2,000 

 grms. meat. 





Nlfrogon. 

 Grms. 



Carbon. 

 Grms. 



225.4 



85 6 



4.3 



179.0 



218 9 



Nitrogen. 

 Grma. 



85.00 



84.38 

 1.00 



85.'i8 

 -0.38 



Carbon. 



Qrnis 



813.0 



50.6 



6.7 



213.6 



270,9 



+ 42.1 



Nitrogon. 

 Grms. 



Carbon. 

 Grms. 



Fed 



Kxcreiecl in 



Urme , 



Dnng 



Befipiration., 



Total exoi etion ..... 



61.20 



5910 

 0.60 



59 70 



68.0 



66.5 

 0.8 



67.3 



250.4 



40 

 54 



158 3 

 203 7 



Gam ( + )orLoss(— ). 



+ 1,50 



+6.5 



+0.7 



+ 46.7 



*Zeitsckrift f. Biologie, VII., 433. 



