On the genesis of the species / by St. George Mivart.

Date:
1871
Catalogue details

Licence: Public Domain Mark

Credit: On the genesis of the species / by St. George Mivart. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    11.] Let the fact of the occurrence of occasional, severe droughts in the country which that animal has inhahited be granted. In that case, when the ground vegetation has been consumed, and the trees alone remain, it is plain that at such times only those individuals (of what we assume to be the nascent giraffe species) which were able to reach high up would be preserved, and would become the parents of the following generation, some individuals of which would, of course, inherit that high-reaching power which alone preserved their parents. Only the high- reaching issue of these high-reaching individuals would again, ccef-eris paribus, be preserved at the next drought, and would again transmit to their offspring their still loftier stature; and so on, from period to period, through seons of time, all the indi- viduals tending to revert to the ancient shorter type of body, being ruthlessly destroyed at the occurrence of each drought. (1.) But against this it may be said, in the first place, that the argument proves too much ; for, on this supposition, many species must have tended to undergo a similar modification, and we ought to have at least several forms, similar to the giraffe, developed from different Ungulata.^ A careful observer of animal life, who has long resided in South Africa, explored the interior, and lived in the giraffe country, has assured the Author that the giraffe has powers of locomotion and endurance fully equal to those possessed by any of the other Ungulata of that continent. It would seem, therefore, that some of these other Ungulates ought to have developed in a similar manner as to the neck, under pain of being starved, when the long neck of the giraffe was in its incipient stage. To this criticism it has been objected that different kinds of animals are preserved, in the struggle for life, in very different 1 The order Ungulata contains the hoofed beasts ; that is, all oxen, deer, anteolpes, sheep, goats, camels, hogs, the hippopotamus, the different kinds of rhinoceros, the tapirs, horses, asses, zebras, quaggas, &c.
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