Embryonic Types.

Given a pre-conceived idea, and how readily the mind discovers confirmation of it in a thousand trivial circumstances. The criminal detects the reflection of his guilt in every human eye; the jealous Moor found fatal confirmation of his mistress's faithlessness in the generous impulses of a good heart; and who shall say how many innocent men have forfeited life and freedom through a damning chain of false suggestions. Even the gambler never fails to find a connected system in the uncertain round of chances that are luring him onward to destruction. But no gambler ever clung to straws so frail as those which have been gravely contended for as great planks in the Evolution platform. The argument based on what is termed Embryology is one of the most ridiculous of these. Darwin and Huxley were content to indicate the broad fact that the human ovum is no larger than page 20 that of a dog, about 1-125th of an inch in diameter; that in the early stages of development it is impossible, among the vertebrate animals, to distinguish one from the other, all being developed in the same way; and that the more closely animals resemble one another in adult structure, the longer and more intimately do their embryos retain a general identity in appearance. Hæckel, however, whose theories—plastidule souls, et hoc genus omne—distinguish him as a man who will not stick at trifles, went a stage further. He devised the four plates exhibited by Mr. Denton in illustrating his lectures, representing various stages in the embryonic development of a man, a dog, a chicken, and a tortoise. Then pointing to six fissures which mark the embryo mammal at a very rudimentary period, he exclaims: "Ah, don't you see how like gills these are—old mother cod has left her mark. "Pointing to the rudimentary development of the spinal column not yet filled out, new ecstasies seize the agitated professor, and he gasps: "See now, we've got the tail; you may drop it hereafter, but there's no getting away from it here." But as one sceptical writer has pointed out, a close examination of Hækel's plates makes it evident, from the abnormal size of the head in the embryo tortoise, that the tortoise must have descended from the man, and not man from the tortoise, while the fish-gills have got into the wrong place, being right across the front of the thorax instead of at the side, where as is shown by Hækel's own drawings of the embryonic fish, the true gills are actually developed. The upper fissures or folds on the embryo of the mammal, turn out upon Hækel's confession to be the rudimentary jaws: "The first pair of gill-arches differentiate into the rudiments of the upper and lower jaws." Carl Ernest Von Baer, who was described by Hækel himself as "our greatest naturalist," and "a gifted and profound thinker and biologist," until he vigorously assailed Evolution, when Hækel lost faith in him, cleverly satirised the attempt to force man in his embryonic state through the series of lower animals. He demonstrated that the germinal fissures, in the embryo, are appropriate to the vessels afterwards revealed, and that in the whole process of development there is nothing distantly suggestive of change from one type to another. That von Baer is a man who speaks of what he knows in this particular department of scientific research will be admitted when it is mentioned that Huxley places his name first among the scientific investigators who reduced to system the principles of embryonic development.

Assuming, however, for one moment, that these fissures do bear some resemblance to gill arches, and are on the side instead of on the front of the throat, and are not rudimentary jaws, what a daring flight of the imagination would be requisite to establish them as ancestral marks. Darwin tells us that "after twelve page 21 generations the proportion of blood, to use a common expression, from an ancestor is only 1 in I 2048." Starting with these figures, Mr. A. W. Hall, an American writer, has calculated that at the l00th generation the proportion of ancestral influence would be

One in 1,116,700,203,157,979,981,456,633,757,926.

And to reach the nearest fish a hundred miles of figures would hardly measure the fraction. As the Darwinian theory admits in the law of heredity only a blood transmission, what potent power that ancestral fish must have had to have so impressed all its succeeding progeny countless ages after the use for gills had disappeared. But even Darwin's minute measure of ancestral influence is reduced from an expressible quantity to an absolute myth within the first two or three generations by that constant process of waste which brings about a complete change in the component parts of every body within the life of a single individual. Huxley says: "So constant and universal is this absorption, waste, and reproduction, that it may he said with perfect certainty that there is left in no one of our bodies at the present moment a millionth part of the matter of which they were originally formed."^* Yet H[unclear: ac]kel assures us, with respect to this childish attempt at resemblance, "I see one of the most important and irrefutable proofs of the theory of descent."^†

Von Baer depicts the bird as retaliating the argument of descent upon man by shewing that, in the embryonic state, the human embryo has the same kind of airless bones, the same rudimentary head, the same thin feathershafts, but that man never advances to that highly organised state which would fit him for flight, nor develops on his skin a warm coat of feathers, or, as an attachment to his skull, so useful an appendage as a beak All that can be affirmed scientifically is what Huxley has advanced, that the ovules of every species of mammalia so closely resemble each other as to elude microscopic observation. But Tyndall very justly observed in his address as President of the British Association in 1870, that the microscope is useless, and may be positively mischievous when employed in determining the essential qualities of germ structure, which it is as incapable of discriminating as the changes of crystallization or the qualities of a diamond. We know, absolutely, from the results, that whatever the relative proportion of size and microscopic appearance, every ovum must be as essentially different in its nature and qualities from every other germ, as the fully developed products are different from each other. Darwinism, to teach any lesson of evolution from the identity of ovules, should be able to show that the ovum of a dog will equally well produce a wolf, a lion, or a monkey. Nay, page 22 accidents of this kind ought to be of common occurrence, and the failure of species to propagate with each other is due to a strange and unaccountable perversity. While such obstinacy exists as an aggressive fact however, similarities in appearance of the ovules teach us how utterly baffled all science stands in presence of this simple phenomenon of the development of varying life performed right under the microscope. No intelligible suggestion has ever been hazarded in elucidation of the action of the vital forces in the germ, and yet, beaten away discomfited from the simpler inquiry, the learned theorist approaches with unbounded confidence that immeasurably vaster problem, the sources of that infinite variety of life with which the whole earth teems.