MUSEUM OF COMPAKATIVE ZOOLOGY. 



One can hardly fail to be struck by the extreme poverty of this 

 Orthopteran fauna und^ the equator, especially when the abundant 

 vegetation of the higher ground is recalled. That a collector interested 

 solely in insects would obtain more species is no doubt true ; but that 

 no greater variety has been obtained by naturalists intent on securing 

 every possible form of animal life, is complete evidence of the meagre- 

 ness of the fauna. Moreover, we have the expressed opinion of i\Ir. A. 

 Agassiz, who collected insects '' and was amazed at the poverty of the 

 catch." 



If, in examining this fauna, we leave out of consideration, as we cer- 

 tainly should, the five cockroaches which can in no sense be considered 

 endemic, we have but fifteen species left. All these fifteen are distinctly 

 South and Central American in their affinities, and live of them arc 

 apterous or subapterous forms, the wings of which cannot even form a 

 parachute to partially sustain the body, while a sixth, Galapagia, has an 

 apterous female. This large proportion of forms incapable of flight, in 

 an assemblage itself of excessively meagre proportions, can be accounted 

 for, it seems to me, only on the supposition that the Calapagos arc of 

 very recent origin, and have obtained their present Orthopteran fauna 

 by the chance advent of pregnant females as waifs from the nearest 

 shore, or the shore which the currents of the ocean practically make the 

 nearest. An insect that could not lly would here actually stand the best 



