CHEMICAL DYNAMICS OF ANIMAL NUTRITION 145 



From these numbers it is evident that, whereas serum (even 100 

 per cent.) strongly inhibits the rate of autolysis, it does not entirely 

 stop it. 



Series \\. Effect of sera of fed and fasting animals (cats] on autolysis 

 of liver of a fasting animal. 



Series (a). Twenty c.c. of 25 per cent, solution of serum to 4 

 grams liver. Same liver used tor experiment with fed as with fasting 

 animal. 



Serum of fed animal Serum of fisting animal 



Time With serum* Control* Difference With serum* Control* Difference 



7 hours 16-3 2<ro 37 16-5 16-2 o 



9 hours 19-3 27-8 8-5 2i'o 24-0 3 



Total i 2 - 2 Total 3*0 



Here the serum of fed animal exerts an inhibitory action. Note, 

 however, that the numbers under the heading 'control' are higher. 

 This indicates that the serum of the fed animal contains a larger 

 quantity of extractives. 



Series (<). Same as Series (a). Liver and sera from different 

 animals. 



Serum of fed animal Serum of fasting animal 



Time With serum* Control* Difference With serum* Control* Difference 



6\ -hours 18-2 24-0 5'8 19-5 26*6 7-1 



9;^ hours 19*5 25-2 57 22-0 25*0 3-0 



Total i 1*5 Total IOM 



Here the same difference of the inhibitory action is not observed 

 as in Series II (</). From experiments on the composition of serum in 

 Part III, one would not expect to find any very definite relationship 

 between the inhibitory action of the serum and the state of the nutrition 

 of the animal from which it has been obtained. The factors 

 influencing autolysis will be demonstrated later. 



Series III. Effect of the action of the products of try p tic digestion of 

 caseine on autolysis. 



Series IJI (dt). Caseine in with twenty times its weight of water 

 was digested in alkaline solution with trypsine. The mixture was then 

 boiled and made just acid with acetic acid. Ammonia was then added 

 until the reaction was plainly alkaline, and the whole was then concen- 

 trated by gently warming on a water bath. 



