STUDY OF POLYNEURITIS GALLINARUM. 451 



acteristic form and with all the evidences of nerve degeneration, 

 but after a prolonged incubation period — forty-five to ninety- 

 days, or even after one year of such feeding (Eijkman). 



17. When fowls are fed on polished rice and in addition receive 

 daily 10 grams of white wheat bread or 5 cubic centimeters of 

 canned milk, they receive little or no protection from polyneuritis 

 gallinarum. 



18. When fowls are fed on polished rice and in addition receive 

 daily 10 grams of meat cooked or uncooked, 10 grams of potatoes 

 cooked or uncooked, or 5 cubic centimeters of fresh cow's milk, 

 they receive partial protection as indicated by the prolongation 

 of the incubation period. 



19. When fowls are fed on polished rice and in addition receive 

 daily 10 grams of dried peas or 10 grams of peanuts, they receive 

 complete protection for at least sixty days. 



VI. CONCLUSIONS AND DISCUSSION. 



CONCLUSIONS. 



1. In addition to the changes demonstrated above, Funk (22) 

 has shown that chemical changes take place in the brains of 

 fowls suffering from polyneuritis gallinarum. It therefore ap- 

 pears that the disease is not simply a peripheral neuritis as has 

 been generally supposed. On the contrary, the entire nervous 

 system is affected. 



2. The symptoms of the disease are not chiefly referable to 

 degeneration of the peripheral nerves, since the degeneration 

 occurs before symptoms arise, and because advanced degenera- 

 tion may be present accompanied by no symptoms at all, and 

 because degeneration of the nerves remains after recovery has 

 occurred. 



DISCUSSION. 



It is apparent from this study that the symptomatology and 

 pathology of polyneuritis gallinarum can not be regarded as 

 identical with that of beriberi in man. We have never observed 

 any oedema in fowls at all comparable to wet beriberi in man, and 

 while there are undoubtedly slight changes in the heart of fowls 

 suffering from polyneuritis, there is none of the hypertrophy 

 which is such a characteristic finding in human beriberi. In 

 spite of these facts, however, there is more similarity than differ- 

 ence between the two diseases. 



When we consider the etiology of the two diseases, the case is 

 different. The experiments of Eraser and Stanton (23) and of 



