LUTHER BURBANK 



Such is the explanation that the paleo-botanist 

 gives us of the fact that the indigeneous vegetation 

 of America to-day is closely similar to that which 

 stocked the sub-arctic regions of the entire north- 

 ern hemisphere in the geological period known as 

 the Mesozoic a period that seems infinitely 

 remote when measured in terms of human history, 

 yet which in the scale of time as measured by the 

 geologist is relatively recent. 



Such trees as the sequoia, we are told, are sur- 

 vivors of that ancient regime that chanced to iind 

 hospitable shelter on the western slopes of the 

 Sierras. Similarly the tulip tree of the east, with 

 the blossoms that seem anomalous for a tree, 

 should be regarded as the souvenir of a past age 

 a lone representative of vast tribes that once flour- 

 ished in tropical luxuriance in regions that now 

 give scant support to moss and lichen and stunted 

 conifers. 



All in all, we are told, the remaining vegetation 

 of to-day, varied though it seems, is but a scant 

 reminiscence of that of the period preceding the 

 ice ages. Only a few species, relatively speaking, 

 were able to make their migration rapidly enough 

 to escape destruction. These included a certain 

 number, like the sequoia and the tulip tree, that 

 were able to reach coigns of vantage that per- 

 mitted them to exist without changing essentially 



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