EXPERIMENTAL VENOM POISONING IN ANIMALS 115 
ity of blood mostly disappeared, and it remained fluid permanently or for some 
time. The kidneys were often hemorrhagic and swollen; the bladder some- 
times contained bloody urine, and the urine was slightly albuminous. ‘The 
irritability of sciatic and phrenic nerves was still present after 13 and 28 
minutes respectively. The brain was found mostly congested. 
ANCISTRODON. 
The actions of the venoms of American species, Ancistrodon piscivorus 
and A. contortrix, are the same, and are essentially similar to those of the 
Crotalus on one hand and the Lachesis — including the famous South Ameri- 
can Bothrops lanceolatus and Trimeresurus of Japan —on the other hand. 
As has already been pointed out by Mitchell and Reichert, the venom of the 
water-moccasin contains more neurotoxic constituent than rattlesnake venom, 
and consequently the degree of local lesions is comparatively less, but para- 
lytic effects on the respiratory center and motor nerves are stronger. Flexner 
and Noguchi confirmed these observations. 
LACHESIS. 
The actions of the venom of the snakes belonging to this genus are much 
the same as those of Ancistrodon and still closer to those of the crotalus 
venoms. In these venoms, as has been already described, the locally destruc- 
tive principles predominate, in contrast to the venoms of typical colubrine 
snakes. 
Careful study of the action of the venom of Lachesis or Trimeresurus 
riukiuanus on different animals has been made by Ishizaka,' from which 
we derive the following: 
The mice and rabbits are fairly susceptible to this venom, the former being 
killed in one hour if 0.003 gm. to 0.005 gm. be given subcutaneously, while the 
latter require 0.02 gm. to 0.03 gm. per kilo body-weight to be fatal in 4 to 6 hours. 
The visible symptoms in mice are the local swelling, general depression, and 
dyspnoea. The respiration becomes gradually slower, irregular, shallower, 
and finally there is a complete standstill, without convulsions inagony. The 
heart continues to beat for some time after respiratory cessation. The local 
symptoms appear from 10 to 15 minutes after injection, and the skin presents 
violet-dark discoloration and hemorrhagic cedema. The amount of the venom 
used is a subminimal lethal dose; the inflammatory hemorrhagic tissues 
become necrotic, and after some time the slough is cast off. In rabbits the 
symptoms are about the same —local swelling, hemorrhages, dyspnoea, depres- 
sion, paresis, and slight convulsions before the respiratory cessation. The 
heart beats some minutes after respiration is stopped. The irritability of 
the phrenic nerve and other muscular nerves is found to be present. The 
hemorrhages are constant symptoms and are always more pronounced in the 
lower parts of the body, this perhaps being due to the gravity of the venom. 
eve gr ee ee ee 
1 Ishizaka, Studien tiber Habuschlangengift. Zeit. f. experimentelle Path. u. Therapie, 1907, IV, 88. 
