8 



HISTORY OF 



locked up during the winter, then begin to 

 expand ; vegetables and insects supply abun- 

 dance of food ; and the bird, having more 

 than a sufficiency for its own subsistence, is 



as swallows, the crane, the stork, &c., make long jour- 

 neys in autumn over seas, and a considerable portion of 

 the earth, and remain in warmer regions during winter, 

 until their return in the following spring. 



There is not any bird provided with teeth, but they 

 either tear their food with the beak, or swallow it whole. 

 In birds that live on seeds, and swallow the grains un- 

 broken, they do not pass at once into the stomach, but 

 are previously softened in a crop ( ingluvies, prolobus) 

 abounding with glands, and thence are gradually pro- 

 pelled into the stomach. The latter is in these animals 

 extremely muscular, and so powerful, that, according to 

 the remarkable experiments of Reaumur and others, it 

 is able to break nuts and olive kernels, and to wear the 

 impressions on pieces of money as smooth as paper. In 

 addition, many birds swallow little pebbles, which also 

 contribute to the division and subsequent digestion of 

 their food.* Various carnivorous birds, as falcons, owls, 

 the king-fisher, &c., are unable to digest the bones, hair, 

 &c., of their prey, but vomit them up after each meal, 

 in the form of a round ball.*j* 



Among the peculiarities of the organs of sense in 

 birds, as compared with mammifera, are the want of an 

 external cartilaginous ear, for the purpose of collecting 

 sounds, a deficiency, however, which is compensated 

 for, especially in nocturnal birds of prey, by the ex- 

 tremely regular circular disposition of the feathers in 

 the situation of the ear, and in many, by the super-addi- 

 tion of a movable valve on the external auditory passage. 



Only a very few birds, viz. ducks, and some similar 

 species, appear to possess a real sense of taste : in them 

 the organ is the soft covering of the bill, which is sup- 

 plied with exceedingly large cutaneous nerves, and is 

 very sensible in the Jiving animal. Accordingly it is 

 easy to remark the manner in which ducks prole, as it 

 were, the puddles in search of their food, where they 

 cannot be guided by their sight or smell. 



The voice of birds, particularly the small singing 

 birds, is varied and agreeable ; but they cannot be so 

 correctly said to sing as to whistle, for natural singing 

 is an exclusive privilege of man. Besides the recep- 

 tacles of air already mentioned, their song is accom- 

 plished particularly by the disposition of the larynx, 

 which in birds is not, as in mammifera and amphibia, 

 placed wholly at the upper end of the wind-pipe, but, as 

 it were, separated into two parts, one placed at each 

 extremity. Parrots, ravens, starlings, bull-finches, &c. 

 have been taught to imitate the human voice, and to 

 speak some words ; singing birds also, in captivity, 

 readily adopt the song of others, learn tunes, and can 

 even be made to sing in company, so that it has been 

 possible actually to give a little concert by several 

 bullfinches. In general, however, the song of birds in 

 the wild state appears to be formed by practice and imi- 

 tation. 



Most birds pair in spring ; many, however, as the 

 cross-bill, at the coldest season of the year, after Christ- 

 mas. Our domestic poultry are not confined to any 

 particular time in this respect, but are always capable of 



* Physiologists have differed as to the ohject and use for 

 which stones are thus swallowed. Many have even supposed 

 that it proceeds from stupidity. According to my own inves- 

 tigation, it is an indispensible measure of assistance to diges- 

 tion, by depriving the seeds swallowed of their vitality, with- 

 out which they would not yield to the digestive powers. 



t From a similar source arise the star-shoots, as they are 

 called, viz. the greyish-white, gelatinous lumps, commonly 

 with the convoluted form of intestines, found in meadows, and 

 consisting of half-digested viscera of frogs, which have been 

 rejected by crows, marsh and water birds. See Dr Persoon, 

 in Void's Neuft Magazin, Vol. I. Part 2. p. 56. et seq. 



impelled to transfuse life, as well as to main 

 tain it. Those warblings, which had been 

 hushed during the colder seasons, now begin 

 to animate the fields ; every grove and bush 



breeding. Some birds remain in company only during 

 the time of pairing; others, as the dove, and house 

 swallow, constantly; others again, as the domestic fow!, 

 and of wild birds, the ostrich, are polygamous. 



The female, when impregnated, is impelled by in- 

 stinct to provide for the future, and to build a nest, to 

 which perhaps, besides the cuckoo, there are very few 

 exceptions, such as the goatsucker. Among polygamous 

 birds, such as the various kinds of poultry, the male hag 

 no share in this business; in those, on the contrary, 

 which live together, as among the singing birds in par- 

 ticular, he also brings materials for constructing the 

 nest, and feeds his mate during her employment. 



The selection of the place in which each species forms 

 its nest, corresponds with its wants and mode of life. 

 Equal care is shown by each in the choice of materials 

 for the composition of the nest. 



The form of the nest is, in different instances, more 

 or less artificial. Many birds, as snipes, the bustard, 

 and lapwing, make merely a dry layer of brushwood, 

 straw, &c., on the surface of the ground; others make a 

 soft but unartificial bed in the holes of walls, rocks, or 

 trees, as the woodpecker, jay, jackdaw, and sparrow. 

 Many, particularly among the gallinse, doves, and sing- 

 ing birds, give their nests the form of a hemisphere, or 

 of a plate ; others, as the wren, the shape of an oven ; 

 others again, as many titmice, the hawfinch, &c., that of 

 a bag, and so forth. 



When the formation of the nest is completed the 

 mother lays her eggs, the number of which varies much 

 in different species. Many water-birds, for instance, 

 lay each time but one egg; most doves, two; gulls, 

 three; ravens, four; finches, five; swallows, six to 

 eight; partridges and quails, fourteen; and the do- 

 mestic fowl, particularly when its eggs are taken away, 

 filty and more.$ Many birds often lay eggs without 

 previous impregnation, which cannot produce young, and 

 are called wind-eggs (ova subventanea, cynosura^ zephy- 

 ria, hypenemia.} 



The formation of the young animal, which in mam- 

 mifera is carried on in the womb, in birds, on the 

 contrary, is completed by the incubation of the egg 

 after it has been deposited. The cuckoo alone does not 

 hatch its eggs, but leaves them to the hedge-sparrow, or 

 water-wagtail, in whose nests it lays them. On the 

 other hand, it is known that capons, dogs, and even 

 men, have hatched eggs. Chickens too, can be easily 

 hatched by artificial rm.ans merely, from heated dung, 

 the lamps of hatching machines, or ovens. Birds are 

 fatigued by long continued incubation; and it is only 

 among those which li\e in pairs, as^doves, swallows, 

 &c., that the male takes any part in the business. The 

 cocks of the canary bird, linnet, goldfinch, &c., though 

 they leave the hatching altogether to the females, supply 

 them during its continuance with food, and in part from 

 their owu crop. 



During incubation, a remarkable process is going 

 forwards, the chick being progressively formed in the 

 egg, and brought daily nearer and nearer to maturity. 

 For this purpose, not only is the yolk specifically lighter 

 than the white, but also that spot on its upper surface 

 the so called cicatricula,} in which the future chick is 



t In this case too, the laying of egs[s appears to be a volun- 

 iary function, in which respect it differs remarkably from the 

 ;otally involuntary parturition of mammifera. 



Plin. L. 10. Cap. 55. " Livia Augustti, prima sua juventa 

 Tiberio Csesare ex Nerone gravida, cum parere virilem sexum 

 admodum cuperet, hoc usa est puellari augurio, ovum in sinu 

 "overulo, atque cum deponendutn haberet, nutrici per sinum 

 tradendo, ne intermitteretur tepor." 



