464 PHILOSOPHY OF ZOOLOGY. 



nearly of equal thickness throughout, and upwards of 

 twice the length of the body. The salivary glands are 

 much branched, and pour their contents into the entrance 

 of the gulleti The liver, in the anima';s of this genus, is 

 distributed into three separate portions, each of which may 

 be regarded as a distinct liver, an arrangement which is not 

 known to take place in any other animal. The first liver 

 is situate near the middle of the body, on the right side ; 

 while the second is placed nedr the posterior extremity. 

 The ducts enter the cardiac opening of the stomach, each 

 by a separate hole, and seem to occupy the place of the 

 zone of gastric glands observed in birds. The third liver is 

 placed at the posterior end of the gizzard, into which it 

 pours its contents by a short duct. 



The most remarkable feature of the circulating system, 

 is the position of the lungs, at the posterior extremity of the 

 body, Avhich occasions a corresponding arrangement in the 

 connecting organs. The entrance to the pulmonary cavity 

 is immediately above the anus. The vessels in which the 

 blood is aerated, are distributed on the roof and sides of 

 the cavity. The pulmonic veins consist of two receptacles, 

 one on each side, extending nearly the length of the body, 

 which may be considered as vena? cavse. These receive the 

 blood by numerous vessels, and convey it directly to the 

 lungs. The aerated blood is conveyed by a systemic vein 

 into a large auricle, seated in front of the lungs, of consi- 

 derable size, with the walls fortified on the interior by 

 branched ligaments. The ventricle is placed at its ante- 

 rior extremity, and separated by two valves. The aorta 

 arises from the opposite side of the ventricle, its main trunk 

 passing on towards the head. 



The male and female organs of generation, although oc- 

 curring in the same individual, appear to occupy different 

 parts of the body. The opening of the male organs is at 



