the hog IXDISTKV. 117 
required fora hog to be on cotton-seed meal before L1 ean be regarded 
as immune. 
Tfu causi of poisoning nothnown. — The poisonous agent of cotton 
seed has not yet been determined. So far chemical and bacteriolog- 
ical examinations have revealed nothing to which can be attributed 
its dangerous character. The injurious action lias been variously 
attributed to the lint on the seed, the large fat content, the highly 
nitrogenous composition, the sharpness of the hulls, the presence of 
a toxin, supposititious chemical or bacteriological changes in the meal, 
formation of poisonous crystals by metabolism, etc. Up to a certain 
period the amount of cotton seed or cotton-seed meal fed does not 
seem to have any influence on the health of the pigs, but the evidence 
on the subject is so meager that one is not justified in drawing con- 
clusions as to the amount of meal that can be fed safely. Curtiss a 
inclines to the toxin theory; he found the amount which proved fatal 
in his investigation to be from 27 to 33 pounds of cotton-seed meal. 
Dinwiddie b holds that the belief that there is a toxic principle in the 
seeds of the cotton plant is the most reasonable one, and one that has 
not been disproved. The action seems to be more virulent with j^oung 
than with older animals, which is characteristic of poisons. He points 
out that the amount fed to pigs is much larger in proportion to their 
body weight than that fed to cattle and suggests this as a reason for 
the supposed greater immunity of cattle. With a 1,000 pound steer, 4 
pounds of cotton-seed meal is an amount equal to 0.4 per cent of the 
body weight. In the case of the pigs in the Arkansas experiments 
the proportion was about 1.5 per cent of the bod} r weight at the begin- 
ning of feeding. The amount of cotton-seed meal eaten per head was 
23, 25, and 15 pounds, respectively, in the three experiments at that 
station. Dinwiddie c calls attention to the fact that other animals are 
susceptible to cotton-seed poisoning and states that guinea pigs, to 
which he fed small quantities of cotton-seed meal along with bran, 
died in from two to three weeks. He also admits the possibility of 
ptomaine poisoning. 
At the Alabama station two of DuggarV experiments resulted 
fatally. In the first experiment the smaller pigs were the first to die. 
They averaged about 61 pounds, and 12.20 pounds of cotton-seed 
meal were eaten by each before death ensued. This was 0.25 pound 
daily per head, or 0.1 pound daily per 100 pounds live weight for 
forty days, and a total of 18.90 pounds per 100 pounds average live 
weight. Larger pigs in this experiment, averaging a little over 70 
pounds, died when 16.60 pounds of cotton-seed meal had been fed per 
head. These pigs were fed 0.41 pound per head daily, or 0.53 pound 
« Bui. No. 28, Iowa Expt. Sta. & Bui. No. 122, Alabama Expt. Sta. 
cBul. No. 76, Arkansas Expt, Sta. 
