SELBORNE, _June 18th_, 1768.
Dear Sir,--On Wednesday last arrived your agreeable letter of June 10th.
It gives me great satisfaction to find that you pursue these studies
still with such vigour, and are in such forwardness with regard to
reptiles and fishes.
The reptiles, few as they are, I am not acquainted with, so well as I
could wish, with regard to their natural history. There is a degree of
dubiousness and obscurity attending the propagation of this class of
animals, something analogous to that of the _cryptogamia_ in the sexual
system of plants: and the case is the same with regard to some of the
fishes, as the eel, etc.
The method in which toads procreate and bring forth seems to be very
much in the dark. Some authors say that they are viviparous, and yet
Ray classes them among his oviparous animals, and is silent with regard
to the manner of their bringing forth. Perhaps they may be ἔσω μὲν
ὠοτὸκοι, ἔξω δε ζωοτόκοι, as is known to be the case with the viper.
The copulation of frogs (or at least the appearance of it) is notorious
to everybody, because we see them sticking upon each other's backs, for a
month together in the spring: and yet I never saw, or read, of toads
being observed in the same situation. It is strange that the matter with
regard to the venom of toads has not been yet settled. That they are not
noxious to some animals is plain, for ducks, buzzards, owls,
stone-curlews, and snakes, eat them, to my knowledge, with impunity. And
I well remember the time, but was not eye-witness to the fact (though
numbers of persons were), when a quack, at this village, ate a toad to
make the country people stare; afterwards he drank oil.
I have been informed also, from undoubted authority, that some ladies
(ladies you will say of peculiar taste) took a fancy to a toad, which
they nourished, summer after summer, for many years, till he grew to a
monstrous size, with the maggots which turn to flesh-flies. The reptile
used to come forth every evening from a hole under the garden steps, and
was taken up, after supper, on the table to be fed. But at last a tame
raven, kenning him as he put forth his head, gave him such a severe
stroke with his horny beak as put out one eye. After this accident the
creature languished for some time and died.
I need not remind a gentleman of your extensive reading of the excellent
account there is from Mr. Derham, in Ray's "Wisdom of God in the
Creation" (p. 365), concerning the migration of frogs from their breeding
ponds. In this account he at once subverts that foolish opinion of their
dropping from the clouds in rain, showing that it is from the grateful
coolness and moisture of those showers that they are tempted to set out
on their travels, which they defer till those fall. Frogs are as yet in
their tadpole state; but, in a few weeks, our lanes, paths, fields, will
swarm for a few days with myriads of those emigrants, no larger than my
little finger nail. Swammerdam gives a most accurate account of the
method and situation in which the male impregnates the spawn of the
female. How wonderful is the economy of Providence with regard to the
limbs of so vile a reptile! While it is an aquatic it has a fish-like
tail, and no legs; as soon as the legs sprout, the tail drops off as
useless, and the animal betakes itself to the land!
Merret, I trust, is widely mistaken when he advances that the _rana
arborea_ is an English reptile; it abounds in Germany and Switzerland.
It is to be remembered that the _salamandra aquatica_ of Ray (the
water-newt or eft) will frequently bite at the angler's bait, and is
often caught on his hook. I used take it for granted that the
_salamandra aquatica_ was hatched, lived, and died, in the water. But
John Ellis, Esq., F.R.S. (the coralline Ellis), asserts, in a letter to
the Royal Society, dated June 5th, 1766, in his account of the _mud
inguana_, an amphibious biped from South Carolina, that the water-eft, or
newt, is only the larva of the land-eft, as tadpoles are of frogs. Lest
I should be suspected to misunderstand his meaning, I shall give it in
his own words. Speaking of the _opercula_ or coverings to the gills of
the _mud inguana_, he proceeds to say that, "The form of these pennated
coverings approaches very near to what I have some time ago observed in
the larva or aquatic state of our English _lacerta_, known by the name
of eft, or newt, which serve them for coverings to their gills, and for
fins to swim with while in this state; and which they lose, as well as
the fins of their tails, when they change their state and become land
animals, as I have observed, by keeping them alive for some time myself."
Linnaeus, in his "Systema Naturae," hints at what Mr. Ellis advances more
than once.
Providence has been so indulgent to us as to allow of but one venomous
reptile of the serpent kind in these kingdoms, and that is the viper. As
you propose the good of mankind to be an object of your publications you
will not omit to mention common salad-oil as sovereign remedy against the
bite of the viper. As to the blind worm (_anguis fragilis_, so-called
because it snaps in sunder with a small blow), I have found, on
examination, that it is perfectly innocuous. A neighbouring yeoman (to
whom I am indebted for some good hints) killed and opened a female viper
about the 27th May: he found her filled with a chain of eleven eggs,
about the size of those of a blackbird; but none of them were advanced so
far towards a state of maturity as to contain any rudiments of young.
Though they are oviparous, yet they are viviparous also, hatching their
young within their bellies, and then bringing them forth. Whereas snakes
lay chains of eggs every summer in my melon beds, in spite of all that my
people can do to prevent them; which eggs do not hatch till the spring
following, as I have often experienced. Several intelligent folks assure
me that they have seen the viper open her mouth and admit her helpless
young down her throat on sudden surprises, just as the female opossum
does her brood into the pouch under her belly, upon the like emergencies;
and yet the London viper-catchers insist on it, to Mr. Barrington, that
no such thing ever happens. The serpent kind eat, I believe, but once in
a year; or rather, but only just at one season of the year. Country
people talk much of a water-snake, but, I am pretty sure, without any
reason; for the common snake (_coluber natrix_) delights much to sport in
the water, perhaps with a view to procure frogs and other food.
I cannot well guess how you are to make out your twelve species of
reptiles, unless it be by the various species, or rather varieties, of
our _lacerti_, of which Ray enumerates five. I have not had opportunity
of ascertaining these; but remember well to have seen formerly several
beautiful green _lacerti_ on the sunny sandbanks near Farnham, in Surrey;
and Ray admits there are such in Ireland.