Or again:—
"Common worms stop up their holes with leaves or straws to prevent the frost from injuring them, or the centipes from devouring them. The habits of peace or the stratagems of war of these subterranean nations are covered from our view; but a friend of mine prevailed on a distressed worm to enter the hole of another worm on a bowling green, and he presently returned much wounded about the head, ... which evinces they have design in stopping the mouths of their habitations."[81]
Does it not look as if Dr. Darwin had in his mind the very passage of Buffon which I have been last quoting? and is it likely that the facts which were accepted by Dr. Darwin without question, or the conclusions which were obvious to him, were any less accepted by or obvious to Buffon?
The Goat—Hybridism.
In his prefatory remarks upon the goat, Buffon complains of the want of systematic and certified experiment as to what breeds and species will be fertile inter se, and with what results. The passage is too long to quote, but is exceedingly good, and throughout involves belief in a very considerable amount of modification in the course of successive generations. I may give the following as an example:—
"We do not know whether or no the zebra would breed with the horse or ass—whether the large-tailed Barbary sheep would be fertile if crossed with our own—whether the chamois is not a wild goat; and whether it would not form an intermediate breed if crossed with our domesticated goats; we do not know whether the differences between apes are really specific, or whether apes are not like dogs, one single species, of which there are many different breeds.... Our ignorance concerning all these facts is almost inevitable, as the experiments which would decide them require more time, pains, and money than can be spared from, the life and fortune of an ordinary man. I have spent many years in experiments of this kind, and will give my results when I come to my chapter on mules; but I may as well say at once that they have thrown but little light upon the subject, and have been for the most part unsuccessful."[82]
"But these," he continues, "are the very points which must determine our whole knowledge concerning animals, their right division into species, and the true understanding of their history." He proposes therefore, in the present lack of knowledge, "to regard all animals as different species which do not breed together under our eyes," and to leave time and experiment to correct mistakes.[83]
The Pig—Doctrine of Final Causes.
We have seen that the doctrine of the mutability of species has been unfortunately entangled with that of final causes, or the belief that every organ and every part of each animal or plant has been designed to serve some purpose useful to the animal, and this not only useful at some past time, but useful now, and for all time to come. He who believes species to be mutable will see in many organs signs of the history of the individual, but nothing more. Buffon, as I have said, is explicit in his denial of final causes in the sense expressed above. After pointing out that the pig is an animal whose relation to other animals it is difficult to define, he says:—
"In a word, it is of a nature altogether equivocal and ambiguous, or, rather, it must appear so to those who believe the hypothetical order of their own ideas to be the real order of things, and who see nothing in the infinite chain of existences but a few apparent points to which they will refer everything.