THE 

 ZOOLOGICAL JOURNAL. 



January, 1826. 



Art. XLVI. On the small liorny appendage to the 

 uppei- mandible in neri/ young Chickens. By William 

 Yarrell, Esq. F.L.S. 



[To the Conductors of the Zoological Journal.] 



Gentlemen, 



On mentioning and exhibiting to some friends in the course of 

 a conversation on vaiious ornithological peculiarities, the small 

 horny appendage near the point of the upper mandible in very 

 young chickens, and its use to the animal while confined within 

 the shell of the egg, the subject appeared to them to be worthy 

 of more particular notice. Some works on comparative anatomy 

 were referred to, but without finding any mention of the point in 

 question ; I have therefore ventured to make the present com- 

 munication, and if to your maturer judgment and more extensive 

 reading, it should appear to deserve recording, the insertion of it 

 in your valuable Journal will be esteemed a favour. 



The changes the egg undergoes during incubation, chemical as 

 well as organic, the origin of the bone, and the gradual develop- 

 ment of the various important parts, are subjects that might na- 

 turally be expected to engage the attention and observation of 

 the most eminent anatomists, and I cannot do better than refer 

 the reader to the papers of Sir Everard Home and Dr. Prout, 

 published in the Philosophical Transactions for the year 1822, 

 part ii. (illustrated as the former account is by a series of en- 

 ' Vol. II. 2 E 



