158 PRACTICAL ORNITHOLOGY. 



with a horny substance, and at the base furnished with conical 

 papillre similarly sheathed. 



As to the Organs of Touch, there seems to be no other part 

 than the bill that can be specially referred to as subservient to 

 this faculty. The skin is sentient, but receives impressions 

 only through the medium of the feathers. The bare skin of 

 the feet and cere is never employed as an organ of touch, for 

 which purpose it is obviously ill adapted, being generally much 

 thickened and callous. In all birds the bill is more or less 

 employed as an organ of touch, and in many, as Snipes and 

 Ducks, is abundantly supplied with filaments of a branch of 

 the fifth pair of nerves. 



These observations will suffice to introduce the organs of 

 sense to the notice of the student of Ornithology, who, with 

 the aid of the treatises on Comparative Anatomy, and multi- 

 plied dissections made by himself, may easily acquire a suffi- 

 cient knowledge of the subject. 



The Respiratory Organs of the Rapacious Birds may now 

 be briefly alluded to. I find nothing in the lungs that difters in 

 any remarkable degree from what is observed in the other land 

 birds. The trachea is, in all the species examined by me, con- 

 siderably flattened, of nearly uniform diameter, or somewhat 

 tapering, with numerous rings, which are usually slender, and 

 rather cartilaginous than osseous. In the Vultures, the infe- 

 rior larynx, Plate XIX, Fig. 1, cc, is much flattened, and the 

 trachea bifurcates, b, without having its last ring furnished 

 with a partition ; the bronchial half-rings, c d, are few and 

 very slender, and the lower portion of the bronchi, d e, is en- 

 tirely membranous. The lateral muscles, //, of the trachea 

 are large, and terminate in the sterno-trachealis, fg->fg-, with- 

 out being prolonged in part so as to form a pair of inferior 

 laryngeal muscles. In three respects, then, the trachea of the 

 Vultures differs from that of the Hawks and Owls ; namely, 

 in having no bone of divarication, in being destitute of inferior 

 laryngeal muscles, and in having a large portion of the bronchi 

 membranous. 



