On the Genesis of Species

or Owen's view.-Mr. Wallace.-Professor Huxley.-Objections to sudden changes.-Labyrinthodont.-Potto.-Cetacea.-As to origin of bird's wing.-Tendrils of cl

s the one means of specific origination, but there are difficulties in the way of accounting for such orig

ls of such modifications: by stable being meant that their variations only extend for a certain degree in various directions, like oscillations in a stable equilibrium. This is the conception of Mr. Galton,[76] who compares the development of species with a many facetted spheroid tum

This is notably the case as regards the young oysters already mentioned, which were taken from the shores of England and placed in the Mediterranean, and at once altered their mode of growth and formed prominent diverging rays, like those of the proper Mediterranean oyster; as also the twenty-nine

d instances are given by Mr. Darwin of pony breeds[79] having independently arisen in different parts of the world, possessing a certain similarity in their physical conditions. Also changes due to climate may be brought about at once in a second generation, though no appreciable modification is shown by the first. Thus "Sir Charles Lyell mentions that some Englishmen, engaged in conducting the operations of the Real del Monte Company in Mexico, carried out with them some greyhounds of t

ing more rarefied air, and so survived, but the offspring were directly modified by the action of surrounding conditions. N

ish climate an individual Porto Santo rabbit[84] recovered the proper colour of its fur in rather less than four years. The effect of the climate of India on the turkey is considerable. Mr. Blyth[85] describes it as being much degenerated in size, "utterly incapable of rising on the wing," of a black colour, and "with long pendulous appendages over the beak enormously developed." Mr. Darwin again tells us that there has suddenly appeared in a bed of common broccoli a peculiar variety, faithfully transmitting its newly acquired and remarkable characters;[86] also that there have been a rapid transformation and transplantation of American varieties of maize with a European variety;[87] that certainly "the Ancon and Manchamp breeds of sheep," and that (all but certainly) Niata cattle, turnspit and pug dogs, jumper and frizzled fowls, short-faced tumbler pigeons, hook-billed ducks, &c., and a multitude of vegetable varieties, have suddenly ap

ormities of ferns are sometimes sought after by fern-growers. They are now always obtained by taking spores from the abnormal parts of the monstrous fern; from which spores ferns presenting the same peculiarities invariably grow.... The most remarkable case is that observed by Dr. Godron, of Nancy. In 1861 that botanist observed, amongst a sowing of Datura tatula, the fruits of which are very spinous, a single individual o

her due to external conditions or to obscure internal causes in the organisms which exhibit them. Moreover, these

en comparatively sudden, and of appreciable size and importance? Either hypothesis will suit the views here maintained equally well (those views being oppo

s the idea that species are transmitted by minute and slow degrees."[92] "An innate tendency to deviate from parental type, operating through periods of

to meet with Mr. Darwin's dogmatic assertion that it is "a false belief" that natural species have often originated in

show no inclination to become truly "rudimentary structures." Accordingly he asserts[94] that such rudimentary parts are formed "suddenly, by arrest of development" in domesticat

e never witnessed the origin of a wild species by any process whatever; and if a species were to come suddenly into being in the wild state, as the Ancon Sheep did under domestication, how could you ascertain the fact? If the first of a newly-begotten spec

f which would in most cases be hurtful unless accompanied by other simultaneous and harmonious modifications. If, however, it is not unlikely that there is an innate tendency to deviate at certain times, and under certain conditions, it is no m

f Professor K?lliker's[97] criticisms, he himself says,[98] "We greatly suspect that she" (i.e. Nature) "does make considerable jumps in th

TAL SECTION OF THE TO

tructures as the wonderfully folded teeth of the labyrinthodonts. The marvellously complex structure of these organs is not merely unaccou

a mere rudiment is inexplicable indeed! "How this mutilation can have aided in the struggle for life, we must confess, baffles our conjectures on the subject; for that any very appreciable gai

TTO (PERODICTI

although we shall presently see there are grounds to believe it is not) practically infinite. It is quite true that it is, in general, very unsafe to infer the absence of any animal forms during a certain geological period, because no remains of them have as yet been found in the strata then deposited: but in the case of the Cetace

OF A PLES

ividuals in the struggle for life. If it arose from an aquatic organ, like the wing of the penguin, we have then a singular divergence from the ordinary vertebrate fin-limb. In the ichthyosaurus, in the plesiosaurus, in the whales, in the porpoises, in the seals, and in others, we have shortening of the bones, but no reduction in the number either of the fingers

OF AN ICH

at once removed, the tendril soon straightens itself. But the contact of other tendrils of the plant, or of the falling of drops of rain, do not produce these effects."[102] But some of the zoological and anatomical discoveries of late years tend rather to diminish than to augment the evidence in favour of minute and gradual modification. Thus all naturalists now admit that certain animals, which were at one time supposed to be connecting links between groups, belong altogether to one

AYE-

irds, and cetaceans to fishes. It is almost superfluous to observe that all now agree that

affinity with birds more marked than any other known animals. Now, however, as has been said earlier, it is

s. It now appears that they form with the latter one great group-the ichthyopsida of Professor Huxley-which differs widely from reptile

more special, and no doubt this has been the case in the majority of instances. Yet it cannot be denied that some of the most recently formed fossils show a st

foot. Now hoofed animals are divisible into two very distinct series, according as the number of functional toes on each hind foot is odd or even. And many other characters are found to go with this obvious one. Even the very earliest Ung

ined the balance of probability towards the artiodactyle. Finally, it appears that this very recently extinct beast presents a highly generalized type of structure, uniting in one organic form both artiodactyle and perissodactyle characters, and that in a manner

d by the extinct glyptodon. In that singular animal the spinal column had most of its joints fused tog

SABRE-TOOTHED TIG

. The premolars are molars which have deciduous vertical predecessors (or milk teeth), and any which are in front of such, i.e. between such and the canine tooth. The true molars are those placed behind the molars having deciduous vertical predecessors. Now, as a dentition becomes more distinctly carnivorous, so the hindmost m

ble that certain antique types arrived at a high degree of specialization and then disappeared; but it is manifest they did do so. Still the fact of this early degree of excessive specialization tells to a certain, however small, extent against a progress through excessively minute steps, whether fortuitous or not; as also

ng, at all events, is to be said in favour of the opinion that sudden and appreciable changes have from time to time occurred, however they may have been induced. Marked races have undoubtedly so arisen (some st