228 OPHIDIANS. 
The viper’s (torva and redi) bite also produces gangrene 
(ultimately) and hemorrhages from the different orifices. 
Cases are recorded where the bitten persons fell down imme- 
diately after the bite, and at a later period paralytic symptoms 
always developed themselves. 
Post mortems have shown that the oppression in the chest 
with its torturing anguish (so distinctly characteristic of La- 
chesis niger, Lachesis trigonocephalus, and Elaps corallinus), is 
very frequently caused by the extension of the gangrene to 
the lungs and liver; although death may supervene (as by 
Crotalus), by the depression of the nerve force; so necessary 
is this latter to the sustenance of the functions of life. 
In Lachesis we see the nerve-centres attacked first; the man 
falls as if struck by lightning! Unconsciousness follows (at 
least in some cases) ; the sympatheticus and vagus are attacked, 
thus disturbing the whole machinery of life, and causing the 
decomposition of the blood, thus producing gangrene, which is 
but a consequence of this lack of vitality. 
The Naja tripudians affects especially the pneumogastricus, 
and the neurotic symptoms predominate over the hematic. 
It produces instant paralysis, destroying or annihilating the 
source of nerve-force; affecting first the sensory, and later the 
motor nerves. Hughes states that in the case of the keeper 
killed in the Zoological Gardens in London by the bite of a 
Naja, the air-passages were filled with a frothy mucus, and 
that death ensued from suppression of the respiration. This 
case affords a proof of the preceding statement of its action. 
This indication in the case just cited is a precise counter- 
part of deaths in many cases in verminous or helminthic 
affections. Post mortems invariably show the air-passages 
filled with a frothy mucus. 
A prominent symptom in many cases of Cobra-bites is 
