ZOOLOGY GALAPAGOS ISLANDS 285 



fact does, I must confess, strike my mind fore ibly. Had 

 there been mammals and no reptiles, it would have been 

 quite different. We should then have said that one de- 

 cided fact against the development theory had been ascer- 

 tained. A minor circumstance in the zoology of these 

 islands is worthy of note. The swimming and w T ading 

 birds are less diverse from those of the rest of the world 

 than the terrestrial species, all of which but one are 

 decidedly peculiar. The same holds good regarding the 

 shells and the insects. Here we have the terrestrial an- 

 imals spreading out into numerous variations, according 

 to the greater variety and the more peculiar character 

 of the circumstances determining their organization.* 

 Mr. Darwin has likewise observed such facts in the natu- 

 ral history of solitary islands, as induce him to express 

 his belief that " the waders, after the innumerable 

 web-footed species, are generally the first colonists of 

 small islands." It is his supposition that the birds in 

 those instances are immigrants ; but I must advert to the 

 fact, as strikingly in harmony with my hypothesis of de- 

 velopment, which was certainly formed without any 

 knowledge of this illustration. 



Another mode of proof in the difficult circumstances 

 with which we are dealing, is to show that the hypothe- 

 sis will account, on a principle of law, for certain facts 

 which we must otherwise suppose to be wholly capri- 

 cious and accidental. The hypothesis is, that, as a general 

 fact, the progress of being in both kinds has been from 

 the sea towards the land. Marine species of plants and 

 animals are supposed to be, in the main, the progenitors 

 of terrestrial species. Life has, as it were, crept out oi 

 the sea upon the land. This, of course, leads us to con- 

 sider the distribution of vegetable and animal forms in 

 the sea, and the effect which these may have had in de- 

 termining the Flora and Fauna of particular detached 

 provinces. We would necessarily suppose that any particu- 



But is not that principle utterly absurd, implying as it does that 

 life had stood still in Australia at one point, while it was advancing 

 to the highest forms in other countries ? Nay, that the agencies 

 employed in the formation of rocks had been stopped there, for 

 perhaps a third of the time of the earth's existence ? The note 

 would not be worthy of this analysis, but that the self-compla- 

 cency of the writer is so apt to impose upon reader* who do not 

 inquire for themselves. 

 f See Darwin's Journal of a Voyage Round the World, c. xvii. 



