DISEASES OP THE BRAIN AND NERVES 197 



than wlieii fed with ])i'ead containing yeast. Ilolst found the 

 same to hold true in feeding pigeons witli ship biscuits. When 

 fowls were fed on whoh^ wheat bread, they remained perfectly 

 well for as long as seventy-five days. It is apparent that 

 whole wheat bread contains some element, or elements, lack- 

 ing in the white bread, which is necessary to maintain the 

 in^oper l)odily metabolism. Fowls force-fed came down fully 

 as soon as those that were allow^ed to eat at will, indicating 

 that it is not a matter of how nuich feed is taken, but its 

 quality. . 



Fowls fed on whole corn remain perfectly well for a period 

 of sixty-three days, but when they are fed on the inside of 

 the corn kernel they come down with the disease as when 

 fed on wheat bread. 



Tests were run to determine the effects of a starvation diet. 

 Two fowds were started on normal diet, then the amount was 

 gradually cut down, until after about twenty-one days the 

 birds wtVc receiving nothing but water. One fowl went for 

 thirty-eight days without food and the other for fifty-six 

 days. In neither fowl was there a typical picture of paraly- 

 sis ; the symptoms presented appeared to be due to muscular 



weakness. 



Wellman and Bass produced polyneuritis in fowds by feed- 

 ing in a like manner, sago, boiled wdiite potato, corn starch, 

 Avheat flour, corn grits, boiled sw^eet potato, cream of wdieat, 

 puffed rice and macaroni. 



It is apparent according to the w^ork of Hoist that pigeons 

 fed on biscuits baked of rye flour, either with or without 

 yeast, do not develop polyneuritis, w^hile pigeons fed on wheat 



bread do. 



The following case report gives the clinical picture : 



During the first ten days the fowl ate heartily of diet, and ap- 

 peared at all times active and well, except for more or less diarrhea. 

 On the eleventh day the fowl began to refuse feed and on the fifteenth 

 dav forced feeding commenced. The first symptom of paralysis was 

 noted on the twenty-second day. On this day the fowl was slightly 

 unsteady and stood teetering forward and backward on its toes; 

 when forced to walk it did so with a high step pushing the feet well 

 forward as if trying to brush something from in front of it. Three 

 days later a slight head tremor was noted, and the bird walked with 

 a decidedly staggering gait, but did not fall. Next day both wings 

 drooped, it walked with great difficulty, and every now and then the 

 joint formed by the tibia and the metatarsus seemed to give way and 

 the fowl suddenly assumed a squatting position. It remained in the 

 cage squatted most of the time on the flexed tarsometatarsus, with 

 the extremities also flexed. On the following day the bird could not 

 stand. The comb was cyanotic, there was convulsive movements 

 now and then with retraction of the head. Next day it was pros- 

 trated. The duration of the disease was six days. 



