224 AMEKICA : GEOGEAPHICAL DISTBIBUTION 



besides the truth and picturesqueness of his descriptions of 

 scenery and all else I am constrained to regard him as 

 the first of scientific travellers ; do you ? This is however 

 a digression. 



3. Lyell's showing that distribution is not a thing of the 

 present only or of the present condition of climates and 

 present outline and contours of lands, and Forbes' Essay on 

 the British Flora. 



4. The establishment of the permanence since the Silurian 

 period of the present continents and oceans. Were you not 

 the first to insist on this, or at least point this out ? Do 

 you not think that Wallace's summing up of the proof of it is 

 good ? (I know I once disputed the doctrine, or rather could 

 not take it in but let that pass !) 



5. The Evolution theory. 



6. The discovery of fossil warm plants in high Northern 

 regions, leading to exact ideas as to effect of glacial period 

 as shown by Gray's Essay. 



7. I must wind up with the doctrine of general distribu- 

 tion being primarily from North to South and always along 

 existing continents, with no similar general flow from S. 

 to N. thus supporting the doctrine which has its last 

 expression in Dyer's Essay read before the Geog. Soc., and 

 referred to in my last E.S. Address [1879, p. 15]. Now if 

 this is accepted, we may not too hastily throw overboard 

 Saporta's doctrine of the boreal origination of the main 

 types of vegetation ; and if this again is accepted we cannot 

 altogether neglect Buffon's argument that vegetation should 

 have commenced where the cooling globe was first cold enough 

 to support it, i.e. at a pole ; and lastly, if this is accepted I 

 must bring in Buffon's speculation in its proper chronological 

 order, and put it as No. 2 of the stages that have led up to our 

 present state of knowledge. But I am disposed to regard 

 Saporta's and Buffon's views as too speculative for that and 

 to introduce them at the end. What do you think of this 

 point, and of it all ? 



It is not even on paper, and how I am to get it all in 

 shape before the end of the month passes my limited powers 

 of prevision. 



I have to take some part in this Congress, 1 and by request 



1 The International Medical Congress held in London, in August 1881. 



