ON GENERATION. 197 



wondered at, if we see the poor women, who beg from door to 

 door, when their milk fails, feeding their infants with food which 

 they have chewed and reduced to a pulp in their own mouths. 



The intestines commence in birds, as has been said, from the 

 upper part of the stomach, and are folded up and down in the 

 line of the longitudinal direction of the body, not transversely 

 as in man. Immediately below the heart, about the waist, and 

 where the diaphragm is situated in quadrupeds, for birds have 

 no [muscular] diaphragm, we find the liver, of ample size, 

 divided into two lobes situated one on either side (for birds 

 have no spleen,) and filling the hypochondria. The stomach 

 lies below the liver, and downwards from the stomach comes the 

 mass of intestines, with numerous delicate membranes, full of air, 

 interposed; the trachea opening in birds, as already stated, by 

 several gaping orifices into membranous abdominal cells. The 

 kidneys, which are of large size in birds, are of an oblong 

 shape, look as if they were made up of fleshy vesicles, without 

 cavities, and lie along the spine on either side, with the descend- 

 ing aorta and vena cava abdominalis adjacent; they further ex- 

 tend into and seem to lie buried within ample cavities of the ossa 

 ilia. The ureters proceed from the anterior aspects of the kid- 

 neys, and run longitudinally towards the cloaca and podex, in 

 which they terminate, and into which they pour the liquid 

 excretion of the kidneys. This, however, is not in any great 

 quantity in birds, because they drink little, and some of them, 

 the eagle for example, not at all. Nor is the urine discharged 

 separately and by itself, as in other animals ; but, as we have 

 said, it distils from the ureters into the common cloaca, which 

 is also the recipient of the faeces, and the discharge of which it 

 facilitates. The urine is also different in birds from what it is 

 in other animals; for, as the urine in the generality of animals 

 consists of two portions, one more serous and liquid, another 

 thicker, which, in healthy subjects constitutes the hypostasis or 

 sediment, and subsides when the urine becomes cold ; so is it in 

 birds, but the sedimentary portion is the more abundant, and is 

 distinguished from the liquid by its white or silvery colour ; nor 

 is this sediment met with only in the cloaca, (where it abounds, 

 indeed, and surrounds the faeces,) but in the whole course of the 

 ureters, which are distinguished from the coverings of the 

 kidneys by their white colour. Nor is it only in birds that 



