69 [Vol. XXXV. 



They had been constructed in order to simplify and codify 

 our general conception of any particular family. Un- 

 fortunately, there was a danger that in the multiplication of 

 genera now going on, our conception would be, not simplified, 

 but complicated. They had only to imagine the process 

 carried a few steps further, and all genera would become 

 monotypic. When this happened, the excuse for genera 

 would have ceased to exist, and we should have arrived by 

 a very laborious and painstaking process at the exact position 

 from which we originally set forth. That might appear to 

 be an exaggerated conception of the position, but he believed 

 that colour-pattern was the only factor that would save the- 

 situation, so fine were the distinctions now drawn between 

 trivial variations in the structure of the bill and other 

 organs. 



These distinctions need not, after all, be so very fine, for 

 take the case of the Redshank association. In that group 

 almost every species could conceivably be made the type of 

 a distinct genus, and the same was true of the Dunlin 

 association. Colour-pattern saved the situation. 



Take, again, the famous Ground- Finches of the Galapagos 

 Islands — famous for their association with Darwin's original 

 conception of the origin of species. Mr. Rothschild, in 

 conjunction with Dr. Hartert, had integrated these into one 

 genus, Geospiza, sinking the three other genera — Cactornis, 

 Camarhynchus , and Platyspiza — on account of the comjDlete 

 series of intergradations in the form of the bill alleged to 

 exist. Dr. Lowe had recently spent a considerable time 

 over the study of this group, and his conclusion was that 

 not only was there but one genus, as Mr. Rothschild and 

 Dr. Hartert held, but that there were only three or four 

 species instead of some 34 or 35, and that these species 

 were polymorphic. He had notes to justify this conclusion^ 

 but time prevented him dwelling further on this point. 



He had instanced the case of Geospiza, because of the 

 complete series of intergradations in the form of the bill, 

 which justified us in 'Mumping.^' But in the case of the 

 two Icterine genera Trupialis and Leistes, there was in the 



