SWISS ALPINE PLANTS. 283 



under very different conditions from the Alpine species here and 

 there found in the lowlands of Switzerland,, and that these 

 Alpine inhabitants of the plain exist under different conditions 

 from their fellows of the same species in the polar zone. 



The Swiss alpine species may be surrounded by species widely 

 different from those of the original mountain-abode of the plants. 

 They may be living under different physical conditions ; yet they 

 preserve their specific characteristics for thousands of years and 

 during a succession of innumerable generations ; and it is im- 

 possible to distinguish the descendants of the Alpine drift-flora 

 now living in the Swiss Alps from plants of the drift-flora in 

 Iceland and Greenland. 



Marine animals justify similar observations. The " struggle 

 for existence " was carried on under different conditions by the 

 Norwegian lobsters inhabiting the depths of the Gulf of Quar- 

 nero, in the Adriatic, near Dalmatia, and by their fellows of the 

 north of Europe ; and yet they have preserved their forms and 

 specific characters. Hence, it may be affirmed that no new 

 species has had its origin since the drift-period. A certain 

 number of species have disappeared, and great changes have 

 taken place in the intermixture of forms. Under the influence 

 of climate and of diverse localities, innumerable varieties have 

 produced among themselves* fertile individuals ; but so far as 

 Prof. Heer knows, no new type has appeared. 



A great geological division ended with the Tertiary period, 

 which generally had its own species of plants and animals. The 

 transformation of these organisms of nature occurred either at 

 the end of the Pliocene epoch, or at the beginning of the drift- 

 period ; and there was no slow transition from the ancient to the 

 modern species, but a transformation. 



In the flora and fauna of preceding periods the same facts are 

 observed. The same species maintain their existence through 

 long periods of time, and often in all parts of the globe present 



* Professor Heer agrees with Professor A. De Candolle and Dr. J. D. Hooker 

 that a great number of the so-called species in our recent " Floras " are only 

 varieties, which owe the specific ranks assigned to them only to the constantly 

 increasing tendency to unnecessary subdivision. These varieties and races 

 preserve their characters and prosper, especially where they are distant from 

 their original stocks. 



