88 



In the Madeiras, this diminution and enlargement of 

 stature, accompanied for the most part respectively by 

 the retention and annihilation of the powers of flight, is 

 singularly traceable on the selfsame rocks, particularly 

 the smaller ones of the group. Thus, on the Flat 

 Deserta, or Ilheo Chao, the Scarites abbreviatus, Koll., 

 Laparocerus morio, Schon., and the Helops Vulcanus, 

 Woll., attain a gigantic size ; yet it is on that very island 

 that the Ptinus albopictus, Woll., finds its minimum of 

 development, scarcely exceeding in dimensions some of 

 the larger members of the Trichopterygia. The Deserta 

 Grande has some special modifying capability of its 

 own, the Eurygnathus Latreillei, Lap., Notiophilus ge- 

 minatus, Dej., Zargus pellucidus, Woll., Calathus com- 

 planatus, Koll., Olisthopus Maderensis,Woll.,Caulotrupis 

 conicollis, Woll., Laparocerus morio, Schon., Omias Wa- 

 terhousei, Woll., Helops Vulcanus, Woll., and the Ellip- 

 sodes glabratus, Fab., being also larger on that rock 

 than is typical : all of them, however, with the excep- 

 tion of Notiophilus geminatus, are there, as elsewhere, 

 apterous. 



Other qualifying results, from isolation, are equally 

 apparent. Take colour, for instance ; and we shall per- 

 ceive that in the Dromius sigma, Rossi, it is sensibly 

 affected. The normal state of that insect " does not 

 occur at all in Madeira proper, but only in Porto Santo. 

 True it is that the modifications in the several islands 

 present but slight differences inter se ; nevertheless, 

 being constant, I would lay particular stress upon them, 



