398 A JOURNEY IN BRAZIL. 



of a separate chapter. The reader will find occasional 

 repetitions of facts already stated in the earlier part of 

 the narrative ; but they are retained for the sake of giv- 

 ing a complete and consistent review of the subject at 

 this point of our journey, where it became possible to 

 compare the geological structure of the Amazonian Val- 

 ley with that of the southern provinces of Brazil and of 

 those bordering on the Atlantic coast. 



THE existence of a glacial period, however much derided 

 when first announced, is now a recognized fact. The 

 divergence of opinion respecting it is limited to a ques- 

 tion of extent ; and after my recent journey in the Ama- 

 zons, I am led to add a new chapter to the strange history 

 of glacial phenomena, taken from the southern hemisphere, 

 and even from the tropics themselves. 



I am prepared to find that the statement of this new 

 phase of the glacial period will awaken among my scien- 

 tific colleagues an opposition even more violent than 

 that by which the first announcement of my views on 

 this subject was met. I am, however, willing to bide my 

 time ; feeling sure that, as the theory of the ancient ex- 

 tension of glaciers in Europe has gradually come to be 

 accepted by geologists, so will the existence of like phe- 

 nomena, both in North and South America, during the 

 same epoch, be recognized sooner or later as part of a 

 great series of physical events extending over the whole 

 globe. Indeed, when the ice-period is fully understood, 

 it will be seen that the absurdity lies in supposing that 

 climatic conditions so different could be limited to a small 

 portion of the world's surface. If the geological winter 



