370 DARWINISM chap. 



lands ; and, in the next place, there is not a particle of direct 

 evidence that any such lowering of temperature in inter- 

 tropical lowlands ever took place. The only alleged evidence 

 of the kind is that adduced by the late Professor Agassiz and 

 Mr. Hartt ; but I am informed by my friend, Mr. J. C. Branner 

 (now State Geologist of Ai'kansas, U.S.), who succeeded Mr. 

 Hartt, and spent several years completing the geological 

 survey of Brazil, that the supposed moraines and glaciated 

 granite rocks near Rio Janeiro and elsewhere, as well as the 

 so-called boulder-clay of the same region, are entii'ely ex- 

 plicable as the results of sub-aerial denudation and weathering, 

 and that there is no proof whatever of glaciation in any 

 part of Brazil. 



Loioer Temperature not needed to Explain the Fads. 



But any such vast physical change as that suggested by 

 Darwin, involving as it does such tremendous issues as re- 

 gards its effects on the tropical fauna and flora of the whole 

 Avorld, is really quite uncalled for, because the facts to be 

 explained are of the same essential nature as those presented 

 by remote oceanic islands, between which and the nearest con- 

 tinents no temperate land connection is postulated. In pro- 

 portion to their limited area and extreme isolation, the Azores, 

 St. Helena, the Galapagos, and the Sand^vich Islands, each 

 possess a fairly rich — the last a A'^ery rich — indigenous flora ; 

 and the means Avhich sufficed to stock them Avith a great 

 variety of plants would probably suffice to transmit others 

 from mountain-top to mountain-top in various parts of the 

 globe. In the case of the Azores, Ave have large numbers of 

 species identical Avith those of Europe, and others closely allied, 

 forming an exactly parallel case to the sjDecies found on the 

 various mountain summits Avhich have been referred to. The 

 distances from Madagascar to the South African mountains 

 and to Kilimandjaro, and from the latter to Abyssinia, are no 

 gi'eater than from Sjjain to the Azores, while there are other 

 equatorial mountains forming stepping-stones at about an 

 equal distance to the Cameroons. BetAveen JaA^a and the 

 Himalayas Ave haA'e the lofty mountains of Sumatra and of 

 Xorth-Avestern Burma, forming steps at about the same distance 

 apart ; Avhile betAveen Kini Balu and the Australian Alps we 



