ILLUSTRATIVE OF NATURAL SELECTION. 137 



proportion of the Satyridae and many of the Dana- 

 idse are shade -loving butterflies. This question, of 

 what is to be considered the highest type of any 

 group of organisms, is one of such general interest to 

 naturalists that it will be well to consider it a little 

 further, by a comparison of the Lepidoptera with some 

 groups of the higher animals. 



Mr. Trimen's argument, that the lepidopterous type, 

 like that of birds, being pre-eminently aerial, " there- 

 fore a diminution of the ambulatory organs, instead 

 of being a sign of inferiority, may very possibly in- 

 dicate a higher, because a more thoroughly aerial 

 form," is certainly unsound, for it would imply that 

 the most aerial of birds (the swift and the frigate- 

 birds, for example) are the highest in the scale of 

 bird-organization, and the more so on account of their 

 feet being very ill adapted for walking. But no or- 

 nithologist has ever so classed them, and the claim to 

 the highest rank among birds is only disputed be- 

 tween three groups, all very far removed from these. 

 They are 1st. The Falcons, on account of their 

 general perfection, their rapid flight, their piercing 

 vision, their perfect feet armed with retractile claws, 

 the beauty of their forms, and the ease and rapidity of 

 their motions ; 2nd. The Parrots, whose feet, though 

 ill-fitted for walking, are perfect as prehensile organs, 

 and which possess large brains with great intelligence, 

 though but moderate powers of flight ; and, 3rd. The 

 Thrushes or Crows, as typical of the perching birds, 

 on account of the well-balanced development of their 



