CLASS II. AVES. 9 



than in qnadrupeds. Tlie nasal cavity exhibits but few convohitions, and in some birds the ex- 

 ternal nasal apertures are either entirely wanting or reduced to a very small size. The auditory 

 apparatus is well developed, and the Hearing is very perfect, though there is no external ear. The 

 sense of Taste is enjoyed in a very inferior degree; the Sight surpasses in power any thing with 

 which we are acquainted in other animals. The eyes are large, but have little power of motion; 

 in some birds, as the owls, they are immovable in their sockets. They are furnished with two 

 movable eyelids and a nictating membrane, which performs the process of Avinking, thus shielding 

 and clearing the eyes without closing the sight. The eye is adapted alike to near and distant 

 vision, so that a bird a thousand feet in the air is able to see, on the earth beneath, the small quad- 

 rupeds or reptiles or insects, or even the grain on which it is to feed. By its gift of vision the 

 bird is able to discover at a glance its way amid the mazes of the forest, and to distinguish birds, 

 reptiles, and insects whose colors blend with the objects of nature around and conceal them from 

 the sight of man. 



There is nothing, perhaps, more remarkable in this interesting class of animated beings than 

 the voice. The windpipe is wider and stronger in birds than in any other animals, and usually 

 terminates in a large cavity, which augments the sound. The lungs, too, have greater extent, 

 and as we have stated, communicate with internal cavities which are capable of being expanded 

 with air — thus, besides lightening the body, giving additional force to the voice. The scream of 

 the eagle seventeen thousand feet in the air, and thus more than three miles distant, may be dis- 

 tinctly heard, and the calls of flocks of storks and geese, beyond the reach of sight and equally 

 remote, are often audible. And these wonderful powers of voice are infinitely diversified in their 

 expression and use, from the simplest call to the most complicated and elaborate song. Every 

 species of bird has a peculiarity of voice possessed by no other. By this variety of vocal endow- 

 ment they are enabled to express to one another their wants and passions. This power of com- 

 munication exists not only between the sexes, but between all individuals of the same species. 

 The least experienced observer of nature knows, too, that the approach of danger is expressed by 

 a universally intelligible cry, which, if uttered by the wren, for instance, is understood by the tur- 

 key-cock, and vice versa. Of whatever species the one may be which first perceives the approach 

 of a bird of prey, it is able to excite the attention of all birds in the neighborhood by its peculiar 

 cry of warning. As soon as the blue-tit utters her Iss ! so indicative of fear and terror — which, 

 nevertheless, she seems sometimes to do from pure love of mischief — the wood is silent in an in- 

 stant, and every bird either listens for the enemy's coming, or hastens to the aid of the comrade 

 who is attacked. This peculiarity is so marked, that in Europe the fowlers have not failed to 

 turn it to purposes of profit. They build a hut, thatch it with green boughs, and cover the roof 

 with a plentiful supply of limed twigs. They then display a screech-owl or other bird of prey, 

 imitate the sonorous cry of a jay or woodpecker in fear c.':d distress, and birds of every size and 

 species flock to the hut and are caught. 



The tones of happiness and joy, by which one bir i is able to call forth from another a similar 

 expression of feeling, seem to be almost as universrWy intelligible. Nor is this joy shown by song 

 alone, although when one little creature begins to sing, the whole wood, or, among domesticated 

 birds, the whole room, soon manifests its sympathy by a general chorus. The same is frequently 

 indicated by single notes. In spring and autumn a great variety of species may often be noticed 

 in hedges and bushes, which seem to take great delight in the utterance of a common cry. 

 Again, when in confinement, birds may often be induced to sing by various noises, loud conversa- 

 tion, and above all, by instrumental music, though on wild birds these means would produce no 

 other eff"ect than to frighten them away. 



In many cases, also, different species have a language, which serves for various purposes of mu- 

 tual communication. For instance, ravens, crows, jackdaws, &c., understand and respond, both 

 by voice and action, to each other's call. By imitating the call of the yellow-hammer, the birtl- 

 catchers of Europe succeed in taking the ortolan, the snow-bunting, the reed-bunting, the foolisli 

 bunting, <fec. ; the cry of the chafiinch decoys the mountain-finch, and that of the siskin attracts 

 the citron-finch and the redpole. 



"Every bird," says Bechstein, "has received from nature the power of uttering either a song or 



Vol. II.— 2 



