11 



TUESDAY, FEBKUAEY 3rcl. 



A Lecture on "Birds of Prey" Avas delivered by J. G. 

 GooDCHiLD, Esq.,' of H.M, Geological Survey, F.G.S., F.Z.S., 

 Member of the British Ornithologists' Union. 



The lecturer began by some observations upon the zoological 

 position of Birds of Prey or Aetomorphse, based upon the researches 

 of Huxley, Parker, Garrod, Forbes, Nitzsch, and others, and 

 illustrated his remarks by reference to various tables and diagrams 

 upon the screen. Contrary to the view generally held, the 

 lecturer maintained the opinion that the Aetomorphae, although 

 undoubtedly presenting many points of agreement amongst them- 

 selves in regard both to their external characteristics and to their 

 mode of life, do not form a really natural group like the Passeres, 

 or the Psittaci, but that the group really comprises several 

 assemblages of raptorial forms evolved independently, and at 

 various times in the past, from widely-separated Sauropsidan 

 ancestors. He regarded their present outward similarity of form 

 as due to morphological convergence accompanying progressive 

 adaptation to a common mode of life. The earlier stages of changes 

 of habit likely eventually to lead to such outward changes of form 

 as those referred to may be observed in many widely-separated 

 forms of birds at the present day. It is quite conceivable, for 

 example, that under particular conditions of environment, one of 

 the Passeres, such as a Shrike, might take to living entirely on 

 small mammals and birds. In such a case, if the competition with 

 other birds leading a similar mode of life were severe, any 

 slight modification of form amongst the offspring of such shrikes, 

 as would enable the younger generation to compete successfully 

 with their feUow-birds in the struggle for existence, would be a 

 manifest advantage to the possessor, and would enable that bird to 

 hold its own while others around it would be driven out of the 

 field. Such beneficial modification of form would, of necessity, 

 lead by slow degi-ees to the assumption of the external characteristics 

 of the birds of prey, for the simple reason that those external 

 characteristics are just such as best suit the mode of life of the 

 possessor. Taking the case of the Game birds, again, we find 

 many of them, the common Barn-door Fowl for example, and the 



