20 PEOCEEDINGS OF THE 



made so little use of tlie evidence afforded by Land-Tortoisps. 

 Darwin, no doubt, would bave paid more attention to tbem if he 

 had been in possession of facts with which we are acquainted now. 

 As it is, he saw in them (together with the large Liz;irds) the most 

 characteristic feature of the zoology of the Galapagos ; but he 

 found them illustrative only as far as they couhrmed results 

 obtained from the plants, which had been worked out by the 

 highest authority on geographical botany. 



Mr. Blanford (i8. p. 54), in one of his Anniversary Addresses 

 to the Geological Society, says : — " The occurrence of Land- 

 Tortoises on what appear to be evidently oceanic islands, 

 such as the Galapagos, although unexplained, rendtrs the 

 Chelonia less important as evidence of laud-connection." Of 

 terrestrial vertebrates I do not know of another type which, from 

 its organization and mode of life, would assist Ufore in the solution 

 of that and other problems than Batrachians and Land-Tortoises. 

 There must be a satisfactory way of accounting for t'le presence 

 of those gigantic forms in two island groups separated from the 

 mainland by hundreds of miles. But I confess that theexphma- 

 tion suggested by Mr. "Wallace ('Island Life,' p. 279) does not 

 appeal to me as the probable solution of the problem. He 

 says * : — " Considering the well-known tenacity of life of thes^ 

 animals, and the large number of allied forms which have aquatic 

 or subaquatic habits, it is not a very extravagant supposition that 

 some ancestral form carried out to sea by a flood, was once or 

 twice safely drifted as far as the Gahq^agos, and has originated 

 the races which now inhabit them." Are the difficulties offered 

 in this suggestion not quite as weighty from a biological point of 

 view as the objections raised by geology? We cannot be sur- 

 prised to see the latest student of the Galapagos fauna, Dr. G. 

 Baur, returning for help to the explanation by the long-disputed 

 land-connection in the Tertiary epoch. 



Dr. Baur treats in a series of papers of the very peculiar 

 composition and distribution of the Flora and Fauna of the 

 Galapagos. Tiiese peculiarities have been long known through 

 the labours of Hooker and Darwin, and have been described t by 

 the latter in his admirably simple language. " It is the circum- 

 stance that several of the islands possess their own species of the 

 tortoise, mocking-thrush, finches, and numerous plants, these 

 species having the same general habits, occupying analogous 

 situations, and obviously filling the same place in the natural 

 economy of this Archipelago, that strikes me with wonder. It 

 may be suspected that some of these representative species, at 



* Wallace has misunderstood my words (Gigaut. Laud-Tort. jDp. 8, 9) when 

 he says tliat "Dr. Giinther believes that they (t)ie Galapagos Tortoises) have 

 been originally derived from the American continent." Without committing 

 myself to adherence to either theory, 1 merely indicated the manner in which 

 the advocate or the opponent of the doctrine of a common origin of similar but 

 locally separated types may account for the presence of the Tortoises in distant 

 oceanic islands. 



t Journal of Researches, ed. 1873, p. 397. 



