Lesson 20 Snake poison
How it came about that snakes manufactured poison is a mystery. Over the periods theirsaliva, a mild
, digestive juice like our own, was converted into a poison that defies analysis even today. It was
not forced upon them by the survival competition; they could have caught and lived on prey without u
sing poison, just as the thousands of non-poisonous snakes still do. Poison to a snake is merely a l
uxury; it enables it to get its food with very little effort, no more effort than one bite. And why
only snakes? Cats, for instance, would be greatly helped; no running fights with large, fierce rats
ortussles with grown rabbits -- just a bite and no more effort needed. In fact, it would be an assis
tance to all carnivores though it would be a two-edged weapon when they fought each other. But, of t
he vertebrates, unpredictable Nature selected only snakes (and onelizard). One wonders saliva into w
hy Nature, with respect from that of others, as other on the blood.
In the conversion of saliva into poison, one might suppose that a fixed process took place. It did n
ot; some snakes manufacture a poison different in every respect from that of others, as different as
arsenic is from strychnine, and having different effects. One poison acts on the nerves, the other
on the blood.
The makers of the nerve poison include the mambas and the cobras and theirvenom is called neurotoxic
. Vipers (adders) and rattlesnakes manufacture the blood poison, which is known as haemolytic. Both
poisons are unpleasant, but by far the more unpleasant is the blood poison. It is said that the nerv
e poison is the more primitive of the two, that the blood poison is, so to speak, a newer product fr
om an improved formula. Be that as it may, the nerve poison does its business with man far more quic
kly than the blood poison. This, however, means nothing. Snakes did not acquire their poison for use
against man but for use against prey such as rats and mice, and the effects on these of viperine po
ison is almost immediate.