6 BULLETIN 1138, U. S. DEPARTMENT OF AGRICULTURE. 
of positive symptoms of polyneuritis, (2) death due apparently to 
polyneuritis, or (3). the close of the test. : 
It is not necessary to describe the symptoms of polyneuritis in 
pigeons, as they have been fully stated by other writers. The symp- 
toms of acute polyneuritis are unmistakable. However, even on a 
polished-rice diet, not all birds develop this type of the disease, but 
some may exhibit a chronic form, usually first indicated by the 
regurgitation of food, later by inability to empty the crop, weakness 
in the legs, etc., followed by general prostration, partial paralysis, 
difficult breathing, collapse, and death. As a rule, polyneuritic 
pigeons were promptly fed dried yeast, to which treatment most, 
but not all, cases responded favorably. Usually birds with the acute 
type of the disease yielded to treatment more readily than those 
with the chronic form. 
TESTS WITH POLISHED RICE. 
Feeding tests were carried on with three pens of pigeons on an 
exclusive rice diet in order to establish a basis for comparison with 
pigeons fed on rations containing various proportions of muscle in 
addition torice. The results of these tests are shown in Table 1. 
TaBLE 1.—Results of feeding polished rice to pigeons. 
: 
Pigeon | Survival |Change in 
Ration. No. | period. | weight. Result. 
PEN 1. 
Days. Per cent. 
Rice not heated 2. pee ee = ee 7 19 —20.7  Polyneuritis. 
W025 53 a: a eee ene eee 70 | 21} —15.0 Do. 
WOlS 22 cae ee eee 72 | 35 —17.8 Very thin, weak, end of test. 
MB Yt ENG eeenay Mpeg Pend 2 74 | 35 —31.7 Do. = 
ANVOCTASC: 2-25 5 5 eee a se Sere | 27.9 —21.3 
PEN 2. ; 
Rice heated 2 hours at 130° C__....- 79 | 17| —20.0 | Polyneuritis. 
DOs: S25. ee ee Liat 21 —23.3 Do. 
W023 6.2 530035 ee 76 30 —39.3 Do. 
Do! 2235.43... ee ee 7s 35 —36.9 | Very thin, weak, end of test. 
AVOCTAGC. 22... 2 ee ee ee 25.6 —23.9 
PEN 3. 
Rice heated 2 hours at 130° C_.....- 66 9 —5.8 | Polyneuritis. 
025222202 ee ee 38 1i —13.0 | Do. 
IDO: 2.3 2) ee eae 64 18 —23.3 Do. 
a Bs leper ee Se = oe sa as 67 18 —19.9 Do. 
D0225.2 222 ee ee ee 69 21 —22.4 Do. 
AV CRALC. .- Sree eee nan - een tee ee 15.4 —16.9 
Average; pens 2and 3.= 222-2)” = 2222 -=- 20.5 — 23.4 
Average, pens 1,2, and 3.2. == °=- == =- 22.8 —22.7 
The data presented in Table 1 do not require a detailed discussion. - 
Attention is called to the difference in the survival period of birds in 
a single pen on the same ration. The average survival period of the 
birds in pens 2 and 3, getting heated rice, is seven days less than 
that of the pigeons in pen 1 on the unheated-rice ration; but the loss 
in weight is about the same. The survival period of the birds in 
pen 3 is 12 days less than that of pen 1. In addition to these results, 
the writer has found that when an animal tissue, like liver, normally 
