350 



ORNITHOLOGY. 



have a large exterior conch, in the form of a thin 

 leathery piece of flesh. The internal ear, however, 

 is very large, anil their sense of hearing very quick. 

 The brain of birds is distinguished by its great pro 

 portionate size, and appears to be formed of tubercles, 

 ami not of convolutions. Their digestive powers are 

 very great : the stomach is composed of three parts 

 the crop, which is a thin membranous expansion ; 

 tliesuccenturium, also a membranous pouch, furnish- 

 ed witli a multitude of glands ; and the gizzard, 

 which is provided with two strong muscles, covered 

 inside by a velvet-like cartilage ; here the food 

 is ground, or triturated, and its action is aided by the 

 presence of small stones, which birds swallow for that 

 purpose. The coverings or feathers of birds are ad- 

 mirably calculated for security, warmth, and celerity 

 of motion. They are of three kinds ; down, smaller 

 feathers, and quills (floccce, pluma et pennce.) The 

 feathers which invest the body have small shafts and 

 large vanes, and are placed over each other like 

 shingles, so as, at the same time, to permit the 

 water to run off and to exclude the cold. The down 

 is placed under these, and serves as a further pro- 

 tection against the cold : hence it is most abundant 

 in those species that inhabit the polar regions. The 

 quill feathers are principally found in the wings and 

 tail. The vanes, which in the wing feathers are 

 broad on one side and narrow on the other, consist 

 of a number of small lamina;, which are connected 

 by the interlacement of a multitude of minute 

 bristles. The largest quill-feathers in the wing, or 

 those nearest the extremity, are termed primaries ; 

 those which arise from the fore-arm are called 

 secondaries; and the weaker feathers attached to 

 the humerus are designated as scapulars. The quill- 

 feathers of the tail are large and strong, having their 

 vanes almost equal in size : they are generally twelve 

 in number, but sometimes, especially in the gallina- 

 ceous birds, eighteen or twenty. The feathery cover- 

 ing of birds constitutes their peculiar beauty : on 

 this, nature, particularly in the warmer climates, 

 has lavished the most splendid colours. The size of 

 the wings is not always in proportion to the bulk of 

 the bird, but is accommodated to its manner of living. 

 Accordingly, birds of prey, swallows, and, in general, 

 such birds as are intended to hover a long time in 

 the air, have much longer wings, in proportion to 

 the size of their bodies, than quails, domestic hens, 

 &c. In the ostrich, the cassowary, and the penguin, 

 the primaries are wanting entirely. The flight of 

 birds differs very much from that of bats, insects, 

 and other volant animals. Many birds, as falcons, 

 soar boldly above the clouds, whither no eye can 

 follow them, and hover for many hours, without per- 

 ceptible exertion, in the air. Likewise swallows, 

 larks, and some other kinds of birds, sail to consi- 

 derable distances with little effort ; others, as spar- 

 rows, have a fluttering flight. Some, as the owls, fly 

 without any noise ; others, as the partridge, &c., with 

 a loud whirr. The flight of a young bird resembles 

 the tottering steps of an infant. You see distinctly 

 how anxiously he seeks for the nearest resting-place, 

 and how soon he is tired. The tail serves as a 

 rudder in most birds ; the long legs of the cranes 

 and other waders appear to serve the same purpose. 

 The legs in different genera of this class are so 

 diversified in shape, that many naturalists have con- 

 sidered these differences sufficient for distinguishing 

 marks of different orders. Being adapted either for 

 resting upon trees, for swimming or running, they 

 answer exactly to the wants of each species. From 

 their food, manner of life, and locomotive powers, 

 birds would seem destined to become inhabitants of 

 every part of the globe ; and, in fact, the cold and 

 barren regions of the north and the sultry plains of 



the tropical climates, become the alternate residence 

 of the same birds at diflerent seasons of the year. 

 At particular times in the year, most birds remove 

 from one country to another, or from inland districts 

 to the sea side. The periods of these migrations are 

 observed with wonderful accuracy, though they are 

 somewhat regulated by the temperature of the 

 seasons. Some species, however, are stationary, as 

 many of the birds of prey. (For a particular account 

 of the migration of birds, see the article Migration 

 of Animals.) The food of birds, like that of quad- 

 rupeds, is derived from the animal and vegetable 

 kingdoms, and, like them, they may be divided into 

 the granivorous and carnivorous, and some which 

 hold a middle rank; and their dispositions and 

 habits, as in quadrupeds, are influenced by the 

 nature of their food : whilst the carnivorous are fierce 

 and untameable, the granivorous are mild, gentle, 

 and easily domesticated ; their flesh, also, is more 

 wholesome and palatable. Birds, however, are 

 more indiscriminate in their food than quadrupeds, 

 and more frequently supply the deficiency of one 

 kind of food by another; and in the young state 

 almost all kinds are carnivorous or rather insecti- 

 vorous. In mental capacity, birds fully equal quad- 

 rupeds, and, in some respects, surpass them. Par- 

 rots, starlings, &c., retain in memory many words 

 and phrases which they have been taught, and many 

 singing birds whole melodies. Their powers of 

 memory seem also to be evinced by the fact that 

 birds of passage, after an absence of six months, or 

 even a longer time, and after travelling thousands 

 of miles, return to their former home ; the swallow 

 to her beam, the finch to the tree where last year 

 she reared her young, or where she herself was 

 hatched. The difference between such birds as 

 love to dwell in uninhabited places, secure from 

 persecution, and such as are found in the neighbour- 

 hood of men, surrounded by dangers, is a proof that 

 their prudence, cunning, and docility can be awak- 

 ened and improved. The field sparrow is less cun- 

 ning than the house sparrow, which has daily oppor- 

 tunity to observe the hostile intentions of man. 

 In desert countries, birds will alight upon the 

 barrel of the hunter's gun, when he levels it against 

 them, whilst with us a mere stick borne upon the 

 shoulder excites the suspicions of the wild goose. 

 The voice is a peculiar gift of nature, by which the 

 greater part of birds are distinguished from all the 

 rest of the animal world. The windpipe of birds 

 is composed of entire rings of cartilage, with an 

 exception in the case of the ostrich. At its bifurca- 

 tion is a glottis supplied with appropriate muscles, 

 called the lower or inferior larynx. It is here that 

 the voice of birds is formed ; the vast body of air 

 contained in the air-cells contributes to the force, 

 and the windpipe, by its form and movements, to the 

 modification of the voice. The superior larynx is 

 very simple and unimportant. The gift of song is 

 given to the male birds only, and their notes are 

 mostly an expression of love ; hence they are heard 

 singing chiefly at the time when they are pairing. 

 The birds sing only when they are cheerful. In 

 sadness, during rough weather, and in bodily dis- 

 orders, they are silent. It is commonly said that 

 the gift of song is confined to the birds in northern 

 climates, and that nature, in the warmer regions, has 

 endowed them, instead, with more brilliant colours ; 

 but Foster relates, that in Otaheite the birds sing 

 with charming sweetness ; and Cook, on his first 

 voyage, found the forests of Queen Charlotte's 

 sound, in New Zealand, filled with little birds, 

 whose voices sounded like silver bells. To no 

 other animal have such various tones been granted 

 for giving utterance to different feelings ; hunger, 



