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considering the marked individual deviations exhibited by the animals 
even when treated similarly. One of the factors causing these 
differences seems to be the body weight. The greater this is at the 
beginning of the experiment the longer the period of incubation 
will generally be. 
After the statement that polyneuritis gallinarum can be produced 
apart from any dietary influence, the poison hypothesis has to be 
for the greater part relinquished as being incompatible with our 
evidence and we may be justified in concluding that the influence 
of the diet according as its composition varies, plays a principal 
part in the prevention of the disease, but an inferior part in its 
development. A similar view has already been put forward by me 
with regard to beri-beri in an earlier publication *). The supporters 
of the poison hypothesis could at best still adhere to an endogenous 
poison as resulting from a disturbed metabolism, admissible in star- 
vation; still, the results of the drenching experiments do not support 
this view of the poison hypothesis either. 
As regards the influence of diet in the causation of polyneuritis, 
there is some reason to suppose that its deficient composition aids 
the onset of the disease indirectly in the manner first expounded 
by Grins, as stated before. 
On the other hand it seems hardly permissible to hold with 
CHAMBERLAIN ¢.s. on the basis of the positive findings in their star- 
vation experiments that not partial but general inanition is answerable 
for the disease. We are able to furnish direct evidence for the view 
that, after fasting just as well as after a defective diet, polyneuritis 
depends upon a partial deficiency, as has been shown in a number 
of eases in which the starving animals, directly after the detection 
of the diseasé, were given 8 to 10 grms of yeast for two or three 
consecutive days and in which the symptoms of polyneuritis were 
seen to recede despite a progressive loss of body weight. The favour- 
able effect of yeast, then, proved the same as in the case of poly- 
neuritis produced after a vitamin-poor diet. 
When we consider the neuritis in starved fowls relative to the 
neuritis developing through a free one-sided diet, we shall see that, 
in the latter case, in consequence of the loss of appetite alluded to 
before, a condition may be evoked approximating the condition 
resulting from forced fasting. They agree also in that the disease 
occurs less regularly than after a forced one-sided diet, in which 
1) Ned. Tijdschr. v. geneesk., 1898, I p. 185. 
