TOPOGRAPHY OF THE PACIFIC COAST. 43 



or fir, such as constitute the prevailing arboreal vegetation of 

 that region to-day was, recognized in the collections. 



In answer to a question concerning the climatic conditions 

 of that region during the Miocene, as indicated by this flora, 

 Professor Lesquereux stated that "by the presence of a large 

 number of Laurineae the flora becomes related in its general 

 characters to that of a region analogous in atmospheric circum- 

 stances to Florida." With this view Professor Lester F. Ward 

 fully agrees, and also Mr. F. H. Knowlton, who has lately given 

 much attention to the flora of the auriferous gravels. 



Mr. Knowlton, says "Lesquereux, as already stated, argued 

 that the presence of a large number of lauraceous plants indi- 

 cated a region analogous in atmospheric circumstances to Florida. 

 From my own studies, which embrace a much larger amount of 

 material than Lesquereux had, I am not only prepared to accept 

 this statement but to show that it was even stronger than he 

 could have made it out." 



Florida is a comparatively low country, rising nowhere more 

 than a few hundred feet above the sea, and it is reasonable to 

 infer that during the early gravel period northern California, 

 which was then analogous in atmospheric circumstances to 

 Florida, could not have been a region of high snow-tipped 

 mountains as it is to-day. 



It is well known that during the Miocene tropical conditions 

 extended much farther north than now, and under such circum- 

 stances it is possible that certain forms of plants may have had 

 considerably greater range in altitude than their relatives in 

 California have to-day. 



No doubt the Sierra Nevada existed at that time, but was a 

 very low range, at least in the northern portion, as compared 

 with its present altitude. Yet it was high enough to supply the 

 alder, birch, poplar, and willows, as well as the few pine leaves 

 lately found by Mr. Turner.^ 



The evidence afforded by the flora of the region is in com- 

 plete harmony with the inference drawn from the topographic 

 ^Bulletin Philosophical Society of Washington, Vol. ii, p. 391. 



