196 
Joumal of Agricultural Research v 0 i. xxviii, no. 2 
examinations of the lungs of four rabbits dying from the intravenous injection 
of 50 mgm. of gossypol per kilo in filtered alkaline solution. He reported in part 
as follows: 
I find in three of the animals (rabbits Nos. 114,118, and 119) a congestion of the alveolar capillaries, fairly 
diffuse edema of the lung, and in several sections extravasations of red blood cells into the albuminous exu¬ 
date within the alveoli. On the other hand, rabbit No. 117 shows a relatively normal lung tissue. In one 
animal (rabbit No. 114) polymorphonuclear leukocytes and fibrin also occur in small foci. The pneumonic 
areas in this rabbit are the more interesting because there is no exudate in the lumen of the bronchi. In 
rabbit No. 118 there is a relatively slight admixture of either red or white cells and fibrin in the exudate. 
In rabbit No. 119 there is no outspoken purulent pneumonic condition. 
The frequent lesions observed in Macy and Mendel's series of subacute and 
chronic intoxication were congestion and hemorrhage in the intestines, congestion 
of the liver and kidneys, and edema of the lungs. The lungs examined by Doctor 
Winternitz for the writers came from animals that had succumbed to acute intox¬ 
ication. One animal died before pulmonary complications had time to develop. 
Three animals showed fairly diffuse edema, congestion of alveolar capillaries, 
and, in a few places, extravasation into the exudate in the lumen, of the alveoli. 
The pneumonic condition was secondary. Marked cardiac enlargement (PI. 2, a) 
was observed in the cat described as having had dyspnoea before death. The 
other cats with similar symptoms did not give the positive evidence of cardiac 
enlargement that was shown by this animal. 
SUMMARY 
Gossypol has been fed for long periods to cats and rabbits in dosages small 
enough to avoid marked loss of appetite, yet large enough to produce chronic 
intoxication. The symptoms and lesions observed were loss of appetite with 
the larger dosages, paralysis, with nerve degeneration, shortness of breath, 
cardiac hypertrophy, edema of the anogenital region and of the lungs, and 
effusion into the serous cavities. Spontaneous recovery may occur temporarily 
while gossypol is being administered and the condition of the animal may become 
progressively worse for some time after it is discontinued. 
Following the subcutaneous, intravenous, and intraperitoneal injection of 
gossypol, there is local edema of the lungs, which may be hemorrhagic, and 
effusion into the serous cavities. Blood pressure falls, heart action becomes 
irregular, and death comes from cardiac involvements. 
Pure gossypol is capable of producing nearly all the manifestations reported 
as characteristic of the cottonseed intoxication of farm animals. Therefore the 
conclusion seems warranted that gossypol is the principal causative agent of 
cottonseed poisoning. This conclusion is supported by the fact, established in 
earlier papers of this series ( 9 , 10), that the toxicity of raw cottonseed kernels 
varies nearly directly with their gossypol content, or is only slightly less. Thus 
there can not be much of any other toxic substance in cottonseed kernels unless 
it be some decomposition product of gossypol. The pharmacology of such 
products has not been investigated. 
