288 THE CANADIAN NATURALIST. [Vol. vii^ 



this is the case, some species have disappeared without known 

 successors, and others have come in without known predecessors. 

 Nay whole floras have come in without known origin. Since the 

 Miocene age the great Arctic flora has spread itself all around 

 the globe, the distinctive flora of North Eastern America and 

 that of Europe have made their appearance, and the great Mio- 

 cene flora once almost universal in the Northern Hemisphere has 

 as a whole been restricted to a narrow area in Western and warm 

 temperate North America. Even if with Gray, in his address 

 of two years ago before the American Association, we are to take 

 for granted that the giant Pines (Sequoias) of California are 

 modified descendants of those which flourished all over America 

 *and Europe in the Miocene, Eocene and Cretaceous, we have in 

 these merely an exceptional case to set against the broad general 

 facts. Even this exception fails of evolutionary significance, 

 when we consider that the two species of Sequoia, which have 

 been taken as special examples, are at best merely survivors of 

 many or several species known in the Cretaceous and Tertiary. 

 The process of selection here has been merely the dropping out 

 of some out of several species of unknown origin, and the survival 

 in a very limited area of two, which are even now probably verg- 

 in^*" on extinction l in other words, the two extant species of 

 Sequoia may havo continued unchanged except varietally from 

 Mesozoic times, and other species existed then and since which 

 have disappeared; but as to how any of them began to exist we 

 know nothing, except that, for some mysterious reason, there 

 were more numerous and far more widely distributed species 

 in the early da3^s of the group than now. This is precisely 

 Barrande's conclusion as to the Palaeozoic Trilobites and Cepha- 

 lopods, and my own conclusion as to the Devonian and Carbon- 

 iferous plants. It is rapid culmination and then not evolution 

 but elimination by the struggle for existence. 



The argument deduced from these successive floras reminds 

 one of certain attempts which have been made in England to 

 invalidate Barrande's law in his own special fleld. With a notice 

 of one of these, which emanates from a successful collector of 

 Primordial fossils, I shall close. He says, after referring to the 

 difi'erent species of Paradoxides and allied genera in the Cam- 

 brian : — 



"Other species show various gradations in the eyes and in the 

 pygidium until we attain to P. Davidis, which has small eyes, a small 



