40 



the south. At the same time, the sorts are sometimes so nearly 

 related as to make it certain that they once belonged to the 

 same type. Still further, the large branches of that internal sea, 

 such as the Madeira and the Negro, which are themselves mighty 

 rivers, often produce the same zoological changes. This is par- 

 ticularly observable in the quadrumana and in the gallinaceous 

 birds. The dispersion of the different sorts of B achyurus 

 give a remarkable example of this . fact. The immense range 

 of the Andes has also produced similar effects, and sudden 

 convulsions of nature, such as earthquakes, are known to 

 have had the same consequences. By the same reason, the 

 fresh-water fishes of the Amazonas and its mighty branches 

 are, as a rule, of species different from those of the Parana 

 and Paraguay, for all their head waters are sometimes only 

 a mile or two distant one from the other ; and if this rule 

 presents exceptions, I consider that they are due to accidental 

 inundations that may from time to time unite smaller branches 

 of these mighty streams. 



I submit these considerations with much humility, knowing 

 with what animosity these questions are debated ; but they are 

 the result of a whole life spent in zoological investigations in all 

 parts of the world. I have for many years studied nature in 

 nature itself. 



I cannot close these lines without expressing my best 

 thanks to those who have assisted me. Sir Bedroond Barry, 

 to whom this Colony owes so much, granted me, by a most 

 honourable exception, the loan of several Ichthyological books 

 contained in the Public Library and missing in my own. Every 

 naturalist knows that descriptions must be compared with speci- 

 mens, and it is easy to understand how impossible it is to 

 transport in a public establishment hundreds of preserved fishes 

 which are often of large dimensions. I must also mention 

 Professor McCoy, who did all in his power to assist me; Dr. 

 Black and Mr Le Souef, the President and Secretary of the 

 Acclimatisation Society, who are always ready to devote their 

 time and experience to any undertaking they consider useful to 

 the Colony ; to Messrs. Livington Booke, Morton Alport, and 

 Waterhouse, who have most kindly sent me valuable specimens 

 fron: Hobart Town and Adelaide ; to Messrs. G-eorge Keesley 



