154 



MRS. E. M. ttEID : A COMPABATIVE 



vol. lxxvi, 



the point given by the loci of 100 in the other (fig. 1, p. 150) : 

 that is, the point at which the incoming flora began to enter. 

 Although it made good headway against the already established 

 Chinese-North American flora, by no means all of it was destined 

 to survive. Of the first species to enter, hardly any survived to 



Fig. 2. — Percentage relation between the entire incoming 

 flora and the exotic part of it. 



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the end of the Pliocene. In the time of the Pont-de-Gail flora, 

 though the incoming flora formed more than a third of the whole 

 West European flora, yet only a sixth of it was destined to survive 

 to the end of the Pliocene ; in the Reuverian it formed nearly 

 half the flora, and of this nearly three-quarters was exterminated ; 



