Notes, iii. 8^9. 209 



In tirds there is no bladder whatsoever. 

 •. Of reptile's, the Ophidia are Without a bladder. So are lizards, crocodiles, and some 

 other Saurians. Bot maiiy Saurians knd all Chel6nia (as also Amphibia) have a bladder 

 which appears to be the.remains of the allantois, and which if it be .so is the homologue 

 of the mammalian .bladder. But this bladder is not in direct continuity with the ureters, 

 but opens out from the anterior wall of the cloaca, while the ureters open into the cloaca 

 posteriorly. This bladder, in spite of its position, is supposed to serve as a receptacle 

 of urine, and urinary salts are said to be found in the fluid it contains. Probably, 

 however, its chief function is to serve as a store-house of fluid for the animal's use in 

 times of divDught (cf. Todd's Cycl. i. 104; Darwin, Beagle, p. 383). This bladder 

 acquires its greatest development in the Chelonia-, where it is of very large size. .Thus 

 is explained the statement in the text. . . 



In fishes there is nothing homologous to . the mammalian bladder ; nothing that is 

 developed from an allantois, so far as is known. But in most if hot all osseous fishes, 

 and in some cartilaginous fishes, the ureters either before or after their junction form a 

 dilatation, which is called a, bladder, and doubtless serves as an urinary reservoir. This 

 dilatation is small, and lies behind the intestine, whereas an allantoidean bladder is 

 always in front ; so that it is no wonder it should have escaped A.'s notice. Its presence 

 •hfis indeed escaped some distinguished modem anatomists (cf. M. Edwards, Lemons, 

 vii. 326). In no invertebrate is there a bladder. 



4. A. is mistaken in supposing thaP tortoises drink but little. ' On the contrary, they 

 are very fond of water. Darwin describes them as wearing broad and well-beaten paths 

 to the springs in Chatham Island, and adds: *' Near the springs it was a curious 

 spectacle to behold many of these huge creatures, one set .eagerly travelling onwards with 

 outstretched necks, and another set returning after having drunk their fill. When the 

 tortoise arrives at the spring, quite regardless of any spectator, he buries his head in the 

 water above the eyes, and greedily swallows great mouthfuls at the rate of about ten 

 a minute " ( Voyage of Beagle, p. 383). Had A. known this, he would most certainly 

 have accounted for the tortoise's bladder by its tl^irsty habits. 



6. The lungs of Chelonia are of much greater size than those of most Saurians and 

 Amphibia, and "s'etendent le long du dos jusqu'au bassin au-dessus de tons les visceres " 

 {Cuvier, Zefons, iv. 347). They are moreover not only thus larger; but contain "in 

 correlation with the non-transpirable integument a much greater development of internal 

 parenchyma" {Rolleston, , Forms of An. Life, Ix. ). This comparative abundance of 

 parenchyma is more marked in marine than in other tortoises {Cuvier, Lemons, iv. 324 and 

 332). There can then be no doubt that A. had carefully examined the lungs of 

 tortoises and other reptiles. It is however an exaggeration on his part to say that the 

 lung of a sea-tortoise resembles that of an o:f. The amount of parenchyma is by no 

 means so great. Probably he was led to make the comparison by his having already 

 found a* likeness between the kidney of the ox and that of the sea-tortoise, in its great 

 subdivision. Cf. next chapter. Note i. ' . 



6. According to Perrault exactly the reverse is the case ; the bladder being usually 

 much larger in the land-tortoises than in the sea-tortoises. Cf. M, Edwards, Lemons, 

 vii. 344. . 



(Ch. 9.) 1. A similar statement, that no Ovipara save the tortoises hare kidneys, is 

 made elsewhere {H. A. \\. 16); where also it is said that the kidney of the tortoise 

 consists, like that of the ox, of numerous smaller parts. The chelonian kidney is in fact 

 extremely subdivided on the outer surface ; so that there can be no doubt that A. 

 had examined it. But it is difficult tp understand how the kidneys of other Ovipara 



14 . • 



