CHAP. IV.] EVOLUTION THE KEY TO DISTEIBUTION. 



69 



different groups of animals, were such as would have enabled 

 all the now disconnected groups to have once formed parts of a 

 continuous series. Proofs of such former continuity are con- 

 tinually being obtained by the discovery of allied extinct forms 

 in intervening lands, but the extreme imperfection of the 

 geological record as regards land animals renders it unlikely 

 that this proof will be forthcoming in the majority of cases. 

 The notion that if such animals ever existed their remains 

 would certainly be found, is a superstition which, notwith- 

 standing the efforts of Lyell and Darwin, still largely prevails 

 among naturalists ; but until it is got rid of no true notions of 

 the former distribution of life upon the earth can be attained. 



