740 The Ptomaines and the Snake Poisons . [December, 
Afurther question may here arise : the saliva in all animals 
is constantly being secreted to a greater or less extent, and 
as constantly being swallowed. Why does it not occasion 
injury to the organism ? It is no answer to this question to 
refer to the very similar case of the cobra, which in like 
manner swallows the overflow of its own poison-gland. 
The cause may probably be that the poison is destroyed in 
the intestinal canal by coming in contact with the bile. 
From poisonous saliva as a general case we are naturally 
led to its especial form in rabies. On this subject Dr. 
Gautier has not experimented. The symptoms of hydro- 
phobia, however, differ very strikingly from those produced 
by the ptomaines, by mushroom-poisons, snake-poisons, &c. 
One very characteristic difference is the time of incubation 
which the matter of rabies requires, after its introduction 
into the system, before the morbid symptoms are manifested, 
whilst the evil effects of the poisons above mentioned are 
rapid, if not instantaneous. 
The poisons of inseCts, &c., ejected by a sting at the tail, 
do not for the most part seem likely tobelong to the ptomaines. 
In the bees and the ants the venomous secretion is strongly 
acid, and has been proved to contain the formic acid. Whe- 
ther its effects are in part due to any other principle is still 
an open question. In wasps, however, the venom, as was 
first demonstrated by Prof. Church, and as we have fully 
verified, is decidedly alkaline, and may possibly contain 
some compound of the ptomaine class. 
As far back as the year 1872 Dr. Corre remarked that cases 
of poisoning from the consumption of poisonous fishes re- 
semble entirely, physiologically speaking, those produced by 
the bites of serpents. Hence there is a strong probability 
that the tissues of such fishes contain substances chemically 
identical with the aCtive principle of the venom of serpents 
and with the cadaveric poisons. To what end these poisons 
serve in most cases, or on what account they have been de- 
veloped, is still utterly unexplained. We can see a reason 
why a cobra or a rattlesnake should possess a poison suffi- 
ciently powerful to kill its prey, and that rapidly. But it 
does not appear what the serpent gains by a poison so much 
in excess of what is neeeed for this purpose. The snake is 
not protected against the larger animals by this weapon, 
since if a man, a large dog, a tiger, &c., has been bitten, he 
has still ample time to take vengeance on the assailant. It 
seems, therefore, that serpent-poisons can scarcely have 
reached their present intensity by the action of Natural 
Selection. 
