392 C. M. Child 



fore have been very similar in both at the time of section. But 

 the muscular activity of the headless pieces decreases in general 

 with decrease in length. The longer pieces must therefore use up 

 nutritive supplies more rapidly than the shorter pieces and if 

 degeneration were due to lack of nutrition it must occur earlier 

 and proceed more rapidly in the longer than in the shorter pieces. 

 But exactly the reverse is the case. Moreover, the formation of 

 new intestinal branches several months after section and after the 

 old branches have undergone complete degeneration shows very 

 clearly that sufficient nutritive material is present to allow the 

 development and maintenance of the intestinal branches, when 

 the proper stimulus is present. It seems impossible, therefore, to 

 escape the conclusion that nutritive factors are not the most 

 important in determining the rapidity of intestinal degeneration. 



But when we consider the dynamic conditions resulting from 

 the presence and movements of the intestinal contents, it at once 

 becomes evident that the rapidity of degeneration is in general 

 proportional to the change in these conditions. In the normal 

 animal these conditions remain most nearly normal and after the 

 food taken from without has disappeared from the intestine it still 

 contains a certain quantity of fluid, which moves about in the char- 

 acteristic manner, though its effect must be quantitatively less than 

 when the intestine is well filled. In headless pieces the movements 

 differ more or less from those of the normal animal and are always 

 less energetic and less frequent, hence the functional stimulus 

 from the contents must be less than in normal animals and intes- 

 tinal degeneration must occur more rapidly in such pieces than in 

 normal animals if it is correlated with decrease or absence of these 

 stimuli. Moreover, motor activity of all kinds decreases with 

 decreasing length of the headless pieces and the mechanical stimuli 

 arising from the intestinal contents must decrease similarly, espe- 

 cially in the lateral branches, since the less powerful the muscu- 

 lar contractions, the less frequently do the intestinal contents 

 enter the branches. Consequently degeneration of the intestinal 

 branches must occur with increasing rapidity as the length of the 

 piece decreases, if it is connected with these conditions. 



As shown above, the facts correspond exactly with the require- 



