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 these 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 oeconomy of Providence with regard to the limbs of so vile a reptile! While it is 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 to 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 bides, 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, Ishall give it in his own words. Speaking of the opercula or covering to the gills of the mud inguana, he proceeds to say that 'The forms of these pennated coverings approach 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 a 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 twenty-seventh of 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 an 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.
Letter XVIII
To Thomas Pennant, EsquireSelborne, July 27, 1768.
Dear Sir,I received your obliging and communicative letter of June the 28th, while I was on a visit at a gentleman's house, where I had neither books to turn to, nor leisure to sit down, to return you an answer to many queries, which I wanted to resolve in the best manner that Iam able.
A person, by my order, has searched our brooks, but could find no such fish as the gasterosteus pungitius: he found the gasterosteus aculeatus in plenty. This morning, in a basket, I packed a little earthen pot full of wet moss, and in it some sticklebacks, male and female; the females big with spawn: some lamperns; some bull's heads; but I could produce no minnows. This basket will be in Fleet-street by eight this evening; so I hope Mazel will have them fresh and fair to-morrow morning. I gave some directions, in a letter, to what particulars the engraver should be attentive.
