Evolution, Old & New / Or, the Theories of Buffon, Dr. Erasmus Darwin and Lamarck, / as compared with that of Charles Darwin

by Samuel Butler

But to return to Dr. Darwin.

"When we revolve in our minds," he writes, "first the great changes which we see naturally produced in animals after their nativity, as in the production of the butterfly with painted wings from the crawling caterpillar; or of the respiring frog from the subnatant tadpole; from the boy to the bearded man, from the infant girl to the woman,—in both which cases mutilation will prevent due development.

"Secondly, when we think over the great changes introduced into various animals by artificial or accidental cultivation, as in horses, which we have exercised for the different purposes of strength or swiftness, in carrying burthens or in running races, or in dogs which have been cultivated for strength and courage, as the bull-dog; or for acuteness of his sense of smell, as the hound or spaniel; or for the swiftness of his foot, as the greyhound; or for his swimming in the water or for drawing snow sledges, as the rough-haired dogs of the north; or, lastly, as a play dog for children, as the lapdog; with the changes of the forms of the cattle which have been domesticated from the greatest antiquity, as camels and sheep, which have undergone so total a transformation that we are now ignorant from what species of wild animal they had their origin. Add to these the great changes of shape and colour which we daily see produced in smaller animals from our domestication of them, as rabbits or pigeons, or from the difference of climates and even of seasons; thus the sheep of warm climates are covered with hair instead of wool; and the hares and partridges of the latitudes which are long buried in snow become white during the winter months; add to these the various changes produced in the forms of mankind by their early modes of exertion, or by the diseases occasioned by their habits of life, both of which become hereditary, and that through many generations. Those who labour at the anvil, the oar, or the loom, as well as those who carry sedan chairs or who have been educated to dance upon the rope, are distinguishable by the shape of their limbs; and the diseases occasioned by intoxication deform the countenance with leprous eruptions, or the body with tumid viscera, or the joints with knots and distortions.

"Thirdly, when we enumerate the great changes produced in the species of animals before their nativity, as, for example, when the offspring reproduces the effects produced upon the parent by accident or cultivation; or the changes produced by the mixture of species, as in mules; or the changes produced probably by the exuberance of nourishment supplied to the fetus, as in monstrous births with additional limbs; many of these enormities of shape are propagated and continued as a variety at least, if not as a new species of animal. I have seen a breed of cats with an additional claw on every foot; of poultry also with an additional claw, and with wings to their feet; and of others without rumps. Mr. Buffon mentions a breed of dogs without tails which are common at Rome and Naples—which he supposes to have been produced by a custom long established of cutting their tails close off. There are many kinds of pigeons admired for their peculiarities which are more or less thus produced and propagated.[179]

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"When we consider all these changes of animal form and innumerable others which may be collected from the books of natural history, we cannot but be convinced that the fetus or embryon is formed by apposition of new parts, and not by the distention of a primordial nest of germs included one within another like the cups of a conjurer.

"Fourthly, when we revolve in our minds the great similarity of structure which obtains in all the warm-blooded animals, as well quadrupeds, birds, and amphibious animals, as in mankind; from the mouse and bat to the elephant and whale; one is led to conclude that they have alike been produced from a similar living filament. In some this filament in its advance to maturity has acquired hands and fingers with a fine sense of touch, as in mankind. In others it has acquired claws or talons, as in tigers and eagles. In others, toes with an intervening web or membrane, as in seals and geese. In others it has acquired cloven hoofs, as in cows and swine; and whole hoofs in others, as in the horse: while in the bird kind this original living filament has put forth wings instead of arms or legs, and feathers instead of hair. In some it has protruded horns on the forehead instead of teeth in the fore part of the upper jaw; in others, tusks instead of horns; and in the others, beaks instead of either. And all this exactly as is seen daily in the transmutation of the tadpole, which acquires legs and lungs when he wants them, and loses his tail when it is no longer of service to him.

"Fifthly, from their first rudiment or primordium to the termination of their lives, all animals undergo perpetual transformations; which are in part produced by their own exertions in consequence of their desires and aversions, of their pleasures and their pains, or of irritations or of associations; and many of these acquired forms or propensities are transmitted to their posterity.

"As air and water are supplied to animals in sufficient profusion, the three great objects of desire which have changed the forms of many animals by their desires to gratify them are those of lust, hunger, and security. A great want of one part of the animal world has consisted in the desire of the exclusive possession of the females; and these have acquired weapons to combat each other for this purpose, as the very thick, shield-like, horny skin on the shoulder of the boar is a defence only against animals of his own species who strike obliquely upwards, nor are his tusks for other purposes except to defend himself, as he is not naturally a carnivorous animal. So the horns of the stag are sharp to offend his adversary, but are branched for the purpose of parrying or receiving the thrust of horns similar to his own, and have therefore been formed for the purpose of combating other stags, for the exclusive possession of the females; who are observed like the ladies in the times of chivalry to attend the car of the victor.

"The birds which do not carry food to their young, and do not therefore marry, are armed with spurs for the purpose of fighting for the exclusive possession of the females, as cocks and quails. It is certain that these weapons are not provided for their defence against other adversaries, because the females of these species are without this armour. The final cause of this contest among the males seems to be that the strongest and most active animal should propagate the species, which should thence become improved."[180]