ORGANS OF TASTE. 97 



rarely met with, though in Anas clangula true frontal sinuses are 

 found extending over the whole upper part of the cranium. The 

 nasal cavities are lined by a very vascular mucous membrane. The 

 olfactory nerve ramifies in a radiated manner upon the septum narium 

 and superior turbinated bone only, the two inferior ossa turbinata 

 receiving filaments from the fifth pair. 



A peculiar Nasal Gland for lubricating the surface of the pitui- 

 tary membrane of the nose is very generally found, being rarely 

 wanting, as in the Pigeon, Cuckoo, and Woodcock, and is often very 

 largely developed. It exhibits very great diversities throughout the 

 orders and genera ; in many Birds, as the Palmipedes, e. g. Eudytes, 

 Alca, Diomedea, and in Charadrius, it lies in a deep co3cal depression 

 upon the frontal bone, which is narrower and flatter in the Gulls and 

 Puffins. The gland is of a crescentic shape in most Birds, as the 

 Passeres, Gallinae, Owls, many of the Grallae and Palmipedes, and 

 situated in depressions above the obtuse supra-orbital ridge ; in the 

 Bustard it is placed near to the superior turbinated bone ; in the 

 Rapacious and some of the Wading-birds, as the Heron, it is lodged 

 in the upper part of the orbit, but very rarely, as in the Woodpeckers, 

 in its lower part beneath the eyeball. The two nasal glands often 

 form, as in Charadrius, large cushions upon the forehead, and in 

 these cases the excretory duct perforates the groove of the frontal 

 bone anteriorly, and is continued onward upon the external wall 

 of the nasal cavity. The Ostriches have a nasal gland, but only 

 slightly developed. 



Organs of Taste. 



Covered for the most part by a hard and 'dense epithelium, 

 and having only upon its root some softer sensitive papillae supplied 

 by branches of the glosso-pharyngeal nerve, the Tongue is obviously 

 bur ill adapted to serve as a very refined instrument of taste ; still 

 however the extent to which this function is enjoyed varies in many 

 Birds. 



Setting aside, as belonging rather to the special province of Orni- 

 thology, a detailed description of the great diversities of form and 

 structure which this organ presents in the several genera of Birds, 

 we shall be content with only noticing here some of its most striking 

 modifications. It is of moderately large size, but hard and horny 

 in the Rapaces, Corvidae, &c. ; short, thick, subcylindrical, and soft 

 in the Parrots, where alone it is frequently provided with small soft 



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