Fortunately the fossil human remains of America have been carefully studied by a competent authority who says, "Irrespective of other considerations, in every instance where enough of the bones is preserved for comparison the somatological evidence bears witness against the geological antiquity of the remains and for their close affinity to, or identity with those of the modern Indian. Under these circumstances but one conclusion is justified, which is that thus far on this continent, no human bones of undisputed geological antiquity are known[741]." Hrdli[vc]ka subsequently studied the remains of South America and says, "A conscientious, unbiased study of all the available facts has shown that the whole structure erected in support of the theory of geologically ancient man on that continent rests on very imperfectly and incorrectly interpreted data and in many instances on false premises, and as a consequence of these weaknesses must completely collapse when subjected to searching criticism.--As to the antiquity of the various archaeological remains from Argentina attributed to early man, all those to which particular importance has been attached have been found without tenable claim to great age, while others, mostly single objects, without exception fall into the category of the doubtful[742]." The conclusions of W. H. Holmes, Bailey Willis, F. E. Wright and C. N. Fenner, who collaborated with Hrdli[vc]ka, with regard to the evidence thus far furnished, are that, "it fails to establish the claim that in South America there have been brought forth thus far tangible traces of either geologically ancient man himself or of any precursors of the human race[743]." Hrdli[vc]ka is careful to add, however, "This should not be taken as a categorical denial of the existence of early man in South America, however improbable such a presence may now appear." According to J. W. Gidley[744] the evidence of vertebrate paleontology indicates (1) That man did not exist in North America at the beginning of the Pleistocene although there was a land connection between Asia and North America at that time permitting a free passage for large mammals. (2) That a similar land connection was again in existence at the close of the last glacial epoch, and probably continued up to comparatively recent times, as indicated by the close resemblance of related living mammalian species on either side of the present Behring Strait. (3) That the first authentic records of prehistoric man in America have been found in deposits that are not older than the last glacial epoch, and probably of even later date, the inference being that man first found his way into North America at some time near the close of the existence of this last land bridge. (4) That this land bridge was broad and vegetative, and the climate presumably mild, at least along its southern coast border, making it habitable for man.