226 AMEEICA : GEOGRAPHICAL DISTKIBUTION 



elevations of that continent but runs obliquely from S.W. 

 to N.E., and is sometimes determined by huge sedimentary 

 deposits as in Upper India, at others by very low mountains 

 does this not imply vast oscillations over an already formed 

 land of continental extension ? 



I am doubtful about going into the Flora of past ages, 

 beyond the Tertiary. I quite believe in the sudden develop- 

 ment of the mass of Phanerogams being due to the intro- 

 duction of flower -feeding insects, though we must not forget 

 that insects occur in the coal and may have been flower- 

 feeding too. 



I have dealt with Saporta's view of the polar origin 

 of Floras in my last R.S. Address. 



I hope we may talk over them and many other such 

 matters when too late for my Address ! 



It appears to me that the great Botanical question 

 to settle is, whether the main endemic Southern temperate 

 types originated there and spread Northwards, or whether 

 they originated in the North and have only just reached 

 the South, and have increased and multiplied there (to be 

 turned out in time by the Northern perhaps). The balance 

 of evidence seems to favor the latter view, and if Palae- 

 ontologists are to be believed in crediting our tertiaries 

 (even polar ones ?) with Proteaceae, it would tend to con- 

 firm this view, as do the Cycadeae, now about extinct in 

 the N. Hemisphere and swarming in the South. 



Buffon's and Saporta's views of life originating at a 

 pole, because a pole must have first cooled low enough to 

 admit of it, is perhaps more ingenious than true but is 

 there any reason opposed to it ? If conceded, the question 

 arises, did life originate at both Poles or one only ? or if 

 at both was it simultaneously ? but this is the deepest 

 abyss of idle speculation. Ever yours affectly. 



J. D. HOOKER. 



To the Same 



September 9, 1881. 



Your criticism anent Southern Glacial Epoch is just 

 my loose statement was due to hasty condensation of matter. 

 What I should have said, and did originally in MS., was, 

 that from the appearance of Antarctic plants on mountains 



