212 Letters, ArmouncemeiUs, &;c. 



The Wings of Birds. — Professor Flower, F.R.S., Director of 

 the British Museum of Natural History, gave a lecture ou 

 Friday, 19th February, at the Royal Institution, on the Wings 

 of Birds. He said that the power of flying through the air 

 was one of the chief characteristics of the class of birds. 

 Although some members of the other great divisions of the 

 Vertebrata possessed the power in a greater or less degree, 

 they were exceptional forms, whereas in birds the faculty of 

 flight was the rule, its absence the exception. He then 

 pointed out the peculiar modifications of the fore limb of 

 the bird which fitted it for his use as a flying-organ. In the 

 vast majority of existing birds the wing was constructed 

 upon the same essential type down to all the details of the 

 number, arrangement, and structure of the feathers, and of 

 their position in relation to the different bones constituting 

 the skeleton of the wing, which were fully described and 

 illustrated by diagrams. Minor modifications of this type 

 resulted in organs so diff'erent in appearance and use as the 

 powerful wings of the Albatross and Swift, which enable 

 their possessors almost to live in the air, and those of the 

 Great Auk and Dodo, too small and feeble to raise the body 

 from the surface of the ground. A totally different type, so 

 far as the arrangement and structure of the feathers are 

 concerned, is seen in the fin-like wings of the Penguins — birds 

 which, on this as well as on other grounds, ought to occupy 

 a far more distinct position in the class than has hitherto 

 been accorded to them. A third type of wing is that of 

 the birds of the Ostrich group, in which the feathers are 

 so imperfectly developed as to make them useless as organs of 

 flight. The question which naturally presents itself with regard 

 to these birds is whether they represent a stage through which 

 all have passed before acquiring perfect wings, or whether they 

 are descendants of birds which had once such wings, but which 

 have become degraded by want of use. In the absence of 

 palseontological evidence it is diflicult to decide this point. 

 The complete structure of the bony framework of the Ostriches 

 wing, with its two distinct claws, rather points to its direct 

 descent from the reptilian hand, without ever having passed 



