10 TECHNICAL BULLETIN 134, U. S. DEPT. OF AGRICULTURE 
oxalate rapliidos does not deter a starved rat from eating these 
products. On the day following the feeding of an experimental diet, 
animals that were not in an obviously depressed condition or that 
were not gyrating viciously were offered the regular diet and water. 
All rats that died within five days after ha"vdng been fed squill, and 
in wliich squill symptoms had been produced, were considered to 
have been killed by squill. 
The detailed results obtained from about 3,000 white and 400 wild 
(bro^v^l) rats are reported in Tables 3, 4, and 5. The preparations as 
made were given ''P. C." (pharmacology card) numbers to identify 
them. As these experiments were carried on over several years, the 
date of each series of feeding tests is given to show that there was at 
least a general agreement in susceptibility of test animals throughout 
the entire investigation. The quantities of dried squill powder fed 
are given in grams. The numerator of each fraction shows the 
number of rats dying from the indicated dose within a period of five 
days; the denominator shows the total number of rats fed the indi- 
cated dose. The MLD (minimum lethal dose) was selected as the 
smallest dose of a dried squill powder, in milligrams per kilogram body 
w^eight, that killed all, or practically all, the rats within five days. 
EFFECTS OF SQUILL ON RATS 
Rats that have eaten a toxic dose of squill soon become somewhat 
lethargic. From 4 to 14 hours later they usually exhibit character- 
istic tremors and sensory depression in the hind legs. This is fol- 
lowed by progi-essive paralysis of the trunk and forelegs. Respira- 
tion increases in rate and becomes labored. The animal next starts 
a peculiar, extremely characteristic rotation on its long axis. These 
gyrations have continued, at intervals, for half an hour and some- 
times for 24 hours. The animal rolls over and over for some time, 
and then stops, apparently through fatigue. After resting, it re- 
sumes this gyration. Stimuli, such as a current of air, cause 
prompt resumption of gyrations. Few rats that showed this symp- 
tom recovered. Post-mortem examinations of a number of animals 
indicated acute cardiac dilatation, and hyperemia of the gastrointes- 
tinal tract and omentum. Although no cause for death other than 
acute cardiac dilatation was observed, in some instances the heart 
beat was detected after the cessation of respiration, indicating that 
respiratory paralysis played a part in producing death by squill. 
RESULTS OF INVESTIGATION 
During the progress of this investigation a number of individual 
problems were studied. For clarity of presentation, the results ob- 
tained in each separate study are reported under separate headings. 
The data given in Tables 6 to 13 are drawn from the results in Tables 
2, 3, 4, and 5. 
