628 



ADDENDA. 



having passed the night on these black and naked rocks, have awakened 

 in the morning vs^ith a strong paroxysm of fever." Humboldt thinks that 

 these cases may be explained by the effect produced on the body by the 

 high temperature, which the black rocks, coated with a layer of the oxides 

 of manganese and iron, retain during the night. But it appears to me 

 that the relation is too remarkable to be thus explained, between this 

 fact and those mentioned by Dr. Ferguson, in which the desiccation of 

 nearly bare rock in Spain, and of a very thin bed of earth overlying dry 

 coral-rock in the West Indies, has given rise to the most pestiferous 

 exhalations. 



Page 461. 



The sixth bird, mentioned as an inhabitant of the Galapagos, Mr. 

 Gould now finds is not like the rest, peculiar to these islands, but is a 

 known North American species of Ammodramus. ^ 



Page 465. 



I have given my reason for believing that the Testudo, inappropriately 

 called Indicus, is an aboriginal species of the Galapagos. I now find {Kerr's 

 Voyages, vol. x., p. 373) that as far back as 1708, Woods, Rogers, and 

 Courtney, in their voyage round the world, speaking of the tortoises of 

 these islands, say that it is the opinion of the Spaniards that there is no 

 other in these seas, except at the Galapagos : it is, however, then added, 

 that they are common in Brazil, — a mistake which may be attributed to 

 two different species not having been distinguished. It has been said 

 that the bones of Testudo Indicus were found in numbers in the Isle 

 of France, with some fragments of those of the Dodo ; but M. Bibron — 

 one of the best authorities in Europe on reptiles — informs me that he 

 has reason to believe that a second species has been confounded under 

 this name. 



In the same page I remark that there is every reason for believing that 

 several of the islands possess their own peculiar varieties or species of 

 tortoise, but that my specimens were too small to decide this question. 

 M. Bibron now informs me, that he has seen full-grown animals, brought 

 from this Archipelago, which he considers undoubtedly to be distinct 

 species. At p. 467, I have observed that the specimens of the Ambly- 

 rhyncus cristatus — that extraordinary marine herbivorous lizard — were 

 larger from Albemarle, than from any other island. In this case, also, 

 M. Bibron tells me, he has seen what he considers two species of the., 

 aquatic Amblyrhyncus, besides the terrestrial species. Doubtless the 

 several islands have their own representatives of the Amblyrhyncus, like 



