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XEW YORK ZOOLOGICAL SOCIETY. 



Di:\ELOPMEXT OF THK OSTRICH FEATHER. 



It is probal)lc tliat carlv tlisuse of the wiiis^' as an organ of 

 lliglit in the Cassowar}-, consequent on the restricted and forested 

 concHtion of its habitat, led to a rapid reduction in the number of 

 remiges. We now find only five or six stout, black, polished 

 spines projecting fn>ni the edge of the wing. Exact homologies 

 of these are to be found in the wing of the adult Apteryx. Here 

 we find that the primaries possess a long, stout calamus, with the 

 rhachis very distinct, but weakly developed. In the primary of 

 a nestling Cassowary a correspondingly weak, scanty-vaned 

 rhachis is formed, which ultimately breaks away at I lie umbilicus. 

 Thus, in the adult Cassowary, the primaries are merely enlarged 

 calami, which appear as hard, brittle spines. Their special use, if 

 they have any, is yet to be discovered. The statement that they 

 are of use in defense is ab^urd. ])oth on account of their posi- 

 tion and their weakness. The suggestion that llu'y may aid 

 the bird in extricating itself froiu a tangle of vines and 

 undergrowth is ver\ im])robable. owing to the exceedingly weak 

 musculature. 



The large size and unusual uum1)er of the remiges in the wings 

 of the Ostrich and Rhea may have resulted from their secondary 

 use as aids in swift running against the wind, a kind of half- 

 return of the lifting function of the wings of tluir ancestors. 

 The less reasonable allernalive hypothesis is. ibal ilie line of 

 descent oi Sirnthio was through some long-arnud. muhi-remiged 

 race, with albatrr)ss-like wings. The Emeu and .Apleryx. like 

 the Cassowarv, apparently Ijegan their return to a terrestrial life 

 uf)on islands, or in more or less forested regions, where wings 



