Modifications of Type. 15 with this claim, he believes himself able to disclose the process itself and its necessity. According to his theory, parents or sexual couples will transmit all their characters, including even the smallest varieties, so that the offspring resemble their parents and yet differ from them in a useful, indifferent, or detrimental direction in some exceedingly minute peculiarity. The detrimental deviations would lead to the speedy destruction of their possessors, nor would the indifferent have any prospect of permanent preservation; the useful alone would effect the transformation of the creatures. But by continual accumulation, imperceptibly minute variations may in the course of considerable periods gradually grow up into specific differences. In this development of new forms, creation at the same time, as it were, criticizes its own works, for as each individual or parental pair usually generates far more descendants than can prosper on the earth, there arises between the offspring of the same, as well as between the representatives of the different species, a struggle for existence in which the more vigorous competitors overpower those less favourably equipped. By continued elimination of the feeble members of the species, and by constant transmission of the favourable newly acquired variations, a change of form gradually occurs. The gist and novelty of Darwin's doctrine consists in the selection just described and which is supposed to be carried on by Nature. This process of transmutation of species has therefore been justly spoken of by Nageli as a utilitarian system. When enthusiasm for this novel and bold idea had given way to cooler reflection, it became more and more evident that selection on utilitarian principles could not always have taken place. The evolution of new organs, or the transformation of old, would certainly have required long periods, during which the incomplete novelty, if not directly detrimental, must at least have remained neutral in the struggle for existence. Moreover, it became evident that organs may exist before advantage can be taken of them. Even among the most different races of mankind, a majority of their number possess vocal apparatus admirably adapted to song, although not employed for musical purposes.27 Nor does natural selection explain how the shape and 27 This is admitted by Darwin himself. appearance of the organic world can arouse æsthetic dispositions in sensitive persons. We find not only the beautiful, the graceful, the agreeable, but also the repulsive, the terrible, the ridiculous, and the demoniac, represented in animals or plants. Darwin, in his book on the descent of man, has attempted to overcome this difficulty by a new article of belief, namely, in sexual selection; the female animals being supposed to prefer the male which most actively excites their senses. But in butterflies, particularly in the Sphingidæ, the lower wings are coloured with peculiar brightness and are adorned with gaudy eyes; yet this creature conceals its own decorations when at rest, while all perception of penciling and colour is precluded by its rapid movements when in flight.28 Many finely formed men and women in America and Africa habitually disfigure themselves by placing discs and plugs in their lips and cheeks, and thereby prove that their taste is still undeveloped, so that their other physical beauties are certainly not due to a fortunate selection. Again we find beauties in such members of the animal kingdom as fecundate themselves, and even in the motionless vegetable kingdom. The aspect of an oak during a storm, the mournful appearance of a Deodara, the hues of many a corolla, the graceful lines of trailing vines, the fabric of a rosebud, are all capable of affording us æsthetic satisfaction, and yet any idea of the exercise of sexual selection by these objects is absolutely impossible. Still less can the transmission of prejudicial characters be reconciled with intentional selection. Darwin indeed appeals to the correlation of the constituent parts of an animal body, in consequence of which changes in one part are accompanied by changes in remote portions of the body; but as we cannot demonstrate, or even imagine, the necessity of this correlation, this argument has no foundation. According to the Darwinian theory, the ancestor of modern man must have been a hairy creature, protected from changes of temperature by a furry coat. Yet the loss of this fur could only 28 Darwin, who never conceals anything that disturbs him, gives in his Descent of Man, vol. i. p. 354, a number of cases in which the lower surface of the wings of nocturnal butterflies are brilliantly coloured or adorned with splendid eyes. When at rest these beauties are invariably concealed. Natural Selection. 17 act prejudicially in the struggle for existence.29 In the case of birds the same observation applies to gaudy plumage, which favours the schemes of their enemies, to the boat-like excrescences of their beaks, as well as to the trailing tails which hinder flight and incubation. Thus it is just the new pith of the Darwinian doctrine, namely, natural selection, which still remains unaccredited; nay, Darwin himself, truth-loving as he always is, has openly confessed with regard to the objections made by Nageli and Broca, that in the earlier editions of "The Origin of Species" he has probably ascribed too much to the effects of natural selection and the survival of the fittest.30 We may add that the older history of the organic world exhibits cases in which the extinction of families of animals has been originated by profound alterations of structure which, as far as such inferences are justifiable with regard to phenomena exhibited by fossils, must have been prejudicial to them. The Ammonites, which died out during the cretaceous period, previously began to pass into so-called cripple forms. Their shells, originally curled into a planiform spiral, subsequently become perpendicularly spiral, extend themselves lineally, or bend like a bow, a hook, or a shepherd's crook, or at least distend themselves so much, that the individual convolutions are no longer in contact with one another.31 But this abandonment of the old type was followed by the complete extinction of the family. We, nevertheless, hold the Darwinian doctrine, not indeed as a successful, but yet as the best attempt to explain the connection of the older with the newer creation, and it will only be supplanted by a more satisfactory solution. It is scarcely comprehensible that pious minds can be disquieted by this doctrine, for creation 29 Inveterate disciples of Darwin remind us that if graminivorous animals, such as horses, take to animal food, their bellies lose their hair. Seligmann, Fortschritte der Racenlehre, Geogr. Jahrbuch, vol. iv. p. 288. Gotha, 1872. The ghost Lemur (Tarsius) is, however, a beast of prey. Carl Semper himself witnessed how one of these creatures killed a mouse with a bite, and devoured it (Allgem. Ztg., p. 239. 1873.) Yet we do not find that baldness has been caused by these articles of food. 30 Descent of Man, vol. i. p. 152. 21 Credner, Elemente der Geologie, 1 edit. p. 435. . gains in dignity and importance if it possesses the power of renovation, and of evolving higher perfection. We may remind the religous world of the danger to which they expose themselves by contemning an investigator so highly esteemed as Darwin. When Copernicus came forward with his, as yet, feebly substantiated doctrine of the planetary character of the earth; nay, even later, when the telescope had discovered in the crescent shape of Venus, as well as in Jupiter and its satellites, a testimony confirming that of the senses; and Kepler by his laws had furnished strict proofs of the truth of the Copernican theory, the new revelation was condemned not by the Roman Curia alone, but also by Protestant zealots. The true Creator, because he had acted on the plan pointed out by Copernicus rather than that of Ptolemy, was placed on the Index in the person of those who had made known his system of worlds; they were persecuted as heretics, for whom, as Kepler writes of himself, God waited six thousand years, in order that they might recognize his works. 32 Once more, two creators are represented to us; the Creator as Cuvier pictured him, who destroys his works because he has devised better ones, and the Creator as Darwin pictures him, who created life variable, but foresaw the tendency of this variation of form, and now allows the clock to go undisturbed. A single fossil discovery, which, however, we will not either desire or predict, might any day testify that the true Creator more nearly resembles the Darwinian conception than that of Cuvier; the rash zealots would then have to lament, as did Galileo's tormentors, that they had persecuted the true God for the sake of a scientific phantom. The history of the transmutation theory can already claim a brilliant case of refutation. Cuvier silenced Lamarck, Darwin's precursor, by requiring him to discover the intermediate form between the Palæotherium and the horse of the present day, if a transformation from the older into the newer animal was supposed to have taken place. Were he still alive, Cuvier, seeing in any of our museums the graceful Hipparion of prehistoric times, with its two aborted hoofs, would have been forced to acknowledge with shame that his demand had been strictly fulfilled. 33 32 C. G. Reuschle, Kepler und die Astronomie, p. 127. Frankf. 1870. Climatic Limits to Distribution. 19 Although Darwin has not been able to give strict proof of his theory of the transmutation of species, he has, nevertheless, thoroughly shaken the credit of the opposite theory of the immutability of specific characters, and, in the sphere of ethnology, has corroborated the conjecture that all races have sprung from a single primordial form, and by the accumulation of small differences, rendered persistent by undisturbed transmission, have developed into varieties. This opinion is favoured by a number of facts, which lead us to infer the high antiquity of our race as well as the capacity of man to adapt himself to the greatest contrasts of temperature found on the face of the earth. As far as man has hitherto advanced in the direction of the poles, traces of inhabitants have been discovered; for not long before the sailor Morton and the Eskimo Hans reached Cape Constitution on the west coast of Greenland (81° 22′ north lat.), on June 24th, 1854, they noticed the fragments of a sledge.34 Traces of inhabitants, such as walrus ribs which had been used as sledge-runners, an old knife handle, and some circular stones for fastening tents, were found by the crew of the Polaris at the extremity of West Greenland. 35 These testified to the previous presence of Eskimo, whom in Homeric language we must regard as the "uttermost men (ἔσχατοι ανδρῶν). With the men we also discover the tracks of at least one domestic animal, for the dog has always been his companion. That portion of the earth has yet to be found which could not be inhabited, or at least visited by some race or other. It is true, the transitions from different climates must not be too sudden. Even Icelanders who immigrate to Copenhagen, are apt to perish from consumption,36 although they are of common origin with the Danes, and only eight hundred years ago spoke the same language. While in the New World, and in the Philippine Islands, the Spaniards have adapted themselves to a tropical life,37 the English have been unable to populate India, and the Dutch to people Su 24 Kane, Arctic Explorations, i. 297. Philadelphia, 1856. 36 Waitz, Anthropologie, vol. i. p. 145. 37 Jäger, Reisen in den Philippinen, p. 29. Berlin, 1873. |