A HISTORY OF 



tion : but there are some varieties which we 

 should more attentively observe. All birds 

 have, properly speaking, but one stomach ; 

 but this is very different in different kinds. 

 In all the rapacious kinds that live upon ani- 

 mal food, as well as in some of the fish-feed- 

 ing tribe, the stomach is peculiarly formed. 

 The oesophagus, or gullet, in them, is found 

 replete with glandulous bodies, which serve 

 to dilate and macerate the food, as it passes 

 into the stomach, which is always very large 

 in proportion to the size of the bird, and ge- 

 nerally wrapped round with fat, in order to 

 increase its warmth and powers of digestion. 



Granivorous birds, or such as live upon 

 fruits, corn, and other vegetables, have their 

 intestines differently formed from those of the 

 rapacious kind. Their gullet dilates just 

 above the breast-bone, and forms itself into a 

 pouch or bag, called the crop. This is re- 

 plete with salivary glands, which serve to 

 moisten and soften the grain and other food 

 which it contains. These glands are very 

 numerous, with longitudinal openings, which 

 omit a whitish and a viscous substance. Af- 

 ter the dry food of the bird has been macera- 

 ted for a convenient time, it then passes into 

 the belly, where, instead of a soft, moist sto- 

 mach, as in the rapacious kinds, it is ground 

 between two pair of muscles, commonly called 

 the gizzard, covered on the inside with a 

 stony, ridgy coat, and almost cartilaginous. 

 These coats rubbing against each other, are 

 capable of bruising and attenuating the hard- 

 est substances, their action being often com- 

 pared to that of the grinding teeth in man and 

 other animals. Thus the organs of digestion 

 are in a manner reversed in birds. Beasts 

 grind their food with their teeth, and then it 

 passes into the stomach, where it is softened 

 and digested. On the contrary, birds of this 

 sort first macerate and soften it in the crop, 

 and then it is ground and comminuted in the 

 stomach and gizzard. Birds are also careful 

 to pick up sand, gravel, and other hard sub- 

 stances, not to grind their food as has been 

 supposed, but to prevent the too violent action 

 of the coats of the stomach against each other. 



Most birds have two appendices, or blind- 

 guts, which, in quadrupeds, are always found 

 single. Among such birds as are thus sup- 

 plied, all carnivorous fowl, and all birds of 

 the sparrow kind, have very small and short 

 ones ; water-fowl and birds of the poultry 

 kind, the longest of all. There is still another 

 appendix observable in the intestines of birds, 

 resembling a little worm, which is nothing 

 more than the remainder of that passage by 

 which the yolk was conveyed into the guts of 

 the young chicken, while yet in the egg and 

 under incubation. 



The outlet of that duct which conveys the 



bile into the intestines is, in most birds, a 

 great way distant from the stomach ; which 

 may arise from the danger there would be of 

 the bile regurgitating into the stomach in 

 their various rapid motions, as we see in men 

 at sea ; wherefore their biliary duct is so 

 contrived, that this regurgitation cannot take 

 place. 



All birds, though they want a bladder for 

 urine, have large kidneys and ureters, by 

 which this secretion is made, and carried 

 away by one common canal. " Birds," says 

 Harvey, " as well as serpents, which have 

 spongy lungs, make but little water, because 

 they drink but little. They therefore have 

 no need of a bladder ; but their urine distils 

 down into the common canal, designed for re- 

 ceiving the other excrements of the body. 

 The urine of birds differs from that of other 

 animals : for, as there is usually in urine two 

 parts, one more serous and liquid, the other 

 more thick and gross, which subsides to the 

 bottom ; in birds, the last part is most abun- 

 dant, and is distinguished from the rest by its 

 white or silver colour. This part is found not 

 only in the whole intestinal canal, but is seen 

 also in the whole channel of the ureters, which 

 may be distinguished from the coats of the 

 kidneys by their whiteness. This milky sub- 

 stance they have in greater plenty than the 

 more thin and serous part; and it is of a 

 middle consistence, between limpid urine and 

 the grosser parts of the faeces. In passing 

 through the ureters, it resembles milk curdled 

 or lightly condensed ; and, being cast forth, 

 easily congeals into a chalky crust." 



From this simple conformation of the ani- 

 mal, it should seem that birds are subject to 

 few diseases ; and, in fact, they have but few. 

 There is one, however, which they are subject 

 to, from which quadrupeds are, in a great 

 measure, exempt ; this is the annual moulting 

 which they suffer ; for all birds whatsoever 

 obtain a new covering of feathers once a year, 

 and cast the old. During the moulting sea- 

 son they ever appear disordered ; those most 

 remarkable for their courage, then lose all 

 their fierceness ; and such as a>e of a weakly 

 constitution, often expire under this natural 

 operation. No feeding can maintain their 

 strength ; they all cease to breed at this sea- 

 son ; that nourishment which goes to the pro- 

 duction of the young is wholly absorbed by 

 the demand required for supplying the nas- 

 cent plumage. 



This moulting-time, however, may be arti- 

 ficially accelerated ; and those who have the 

 management of singing-birds frequently put 

 their secret in practice. They inclose the 

 bird in a dark cage, where they keep it ex- 

 cessively warm, and throw the poor little ani- 

 mal into an artificial fever ; this produces the 



