PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 251 
I found that the venom had occasioned intravascular clotting 
in both these frogs. The blood in the whole vascular system was 
coagulated, except in the ligatwred limb. It therefore appeared 
quite likely that the venom had not been circulating sufficiently 
long to produce any influence on the nerve terminations, In the 
remainder of the experiments intravascular clotting was obviated 
by using venom which had previously been heated to 85° C. for a 
minute. Nevertheless the same paralysis followed, but it took 
considerably longer to develope when the same weight of poison 
was employed. 
Experiment [V.—Large male frog, weight 20 grammes, prepared 
as usual. 
12°15 pm., ‘5 ce. of 1% solution of venom previously heated to 
85° C. injected into dorsal lymph sac. 
4:30 ,, respiratory movements feeble; recovers with diffi- 
culty when placed on back. 
5°30 ,, respiration ceased. 
ro KS response to stimulation ; sciatics dissected out. 
Maximum distance between coils when gastrocnemius 
con ed. 
| Blectrodeson | Electrodes on 
| sciatic nerve. | dorsal cord. 
Ligatured limb...| 22 em. | 19 cm. | 
Unligatured limb| 62°5 cm. 27 cm. 
Experiment V.—Lusty frog, weight 18 grammes prepared as usual. 
3:20 p.m., *75 cc. of a 1¥% solution of venom previously heated 
to 85° ©. injected in dorsal lymph sac. 
330, respiratory movements ceased. Moves both legs 
slowly when feet are pinched; turns over with 
difficulty when placed on back. 
334 ,, remains on back without attempting to recover. 
$37 4, all reflex response gone ; sciatics dissected out. 
Maximum distance between coils when gastrocnemius 
contracted. 
Electrodes on | Electrodes on 
| ciatic nerve. | dorsal cord. 
Ligatured limb...) 53 em. | 34 cn. | 
Unligatured limb 60 cm. 39 cm. 
