378 Miscellaneous. 



ibises and cats preserved by the ancient Egyptians being just like 

 those of the present day, could triumphantly add a few hundred 

 thousand years more to the length of the experiment and to the force 

 of their argument. As the facts stand, it appears that, while some 

 Tertiary forms are essentially undistinguishable from existing ones, 

 others are the same with a difference which is judged not to be spe- 

 cific or aboriginal, and yet others show somewhat greater differences, 

 such as are scientifically expressed by calling them marked varieties, 

 or else doubtful species ; while others, differing a little more, are con- 

 fidently termed distinct, but nearly-related species. Now, is not all 

 this a question of degree, of mere gradation of difference ? Is it at all 

 likely that these several gradations came to be established in two totally 

 different ways — some of them (though naturalists can't agree which) 

 through natural variation, or other secondary cause, and some by origi- 

 nal creation, without secondary cause ? We have seen that the judicious 

 Pictet answers such questions as Darwin would have him do, in affirm- 

 ing that, in all probability, the nearly -related species of two successive 

 faunas were materially connected, and that contemporaneous species, 

 similarly resembling each other, were not all created so, but have 

 become so. This is equivalent to saying that species (using the term 

 as all naturalists do and must continue to employ the word) have 

 only a relative, not an absolute fixity ; that differences fully equiva- 

 lent to what are held to be specific may arise in the course of time, 

 so that one species may at length be naturally replaced by another 

 species a good deal like it, or may be diversified through variation or 

 otherwise into two, three, or more species, or forms as different as 

 species. This concedes all that Darwin has a right to ask, all that 

 he can directly infer from evidence. We must add that it affords a 

 locus standi, more or less tenable, for inferring more. 



Here another geological consideration comes in to help on this 

 inference. The species of the later Tertiary period for the most part 

 not only resembled those of our days (many of them so closely as to 

 suggest an absolute continuity), but also occupied in general the same 

 regions that their relatives occupy now. The same may be said, 

 though less specially, of the earlier Tertiary and of the later Secondary; 

 but there is less and less localization of forms as we recede, yet some 

 localization even in palaeozoic times. While in the secondary period 

 one is struck with the similarity of forms and the identity of many 

 of the species which flourished apparently at the same time in all or 

 in the most widely separated parts of the world, in the Tertiary 

 epoch, on the contrary, along with the increasing specialization of 

 climates and their approximation to the present state, we find abun- 

 dant evidence of increasing localization of orders, genera, and species ; 

 and this localization strikingly accords with the present geographical 

 distribution of the same groups of species. Where the imputed fore- 

 fathers lived, their relatives and supposed descendants now flourish. 

 All the actual classes of the animal and vegetable kingdoms were 

 represented in the Tertiary faunas and floras, and in nearly the same 

 proportions and the same diversities as at present. The faunas of 

 what arc now Europe, Asia, America, and Australia differed from 



