298 
PLINT's l^fATTJEAL HISTORY. 
[Book VIIT. 
on the banks of rivers, just as though with a knife. If they 
seize a man by any part of his body, they will never loose 
their hold until his bones are broken and crackle under their 
teeth. The tail is like that of a fish ; in the other parts of 
the body they resemble the otter ; ^'^ they are both of them 
aquatic animals, and both have hair softer than down. 
CHAP. 48. (31.) BEAMBLE- FROGS. 
Eramble-frogs,^^ also, which live both on land and in water, 
are replete with various medicinal substances, which they are 
said to discharge each day, and to take in again with their 
food, of which they only retain the poisonous parts. 
CHAP. 49. — THE sea-calf; beavers; lizards. 
The sea-calf, too, lives equally in the sea and on land^ 
being possessed of the same degree of intelligence as the beaver. 
It vomits forth its gall, which is useful for many purposes in 
medicine ; also the rennet, which serves as a remedy in 
epilepsy ; for it is well aware that it is hunted for these sub- 
The beaver has the most powerful teeth of any animal of the class 
Rodentia, to which it belongs ; it uses them for cutting down trees, with 
which it constructs its habitation. Aristotle, Hist. Anim. B, yiii. c. 5, 
refers to this. — B. 
2^ The tail is covered with a kind of scale, and is flattened ; hut, in its 
internal organization, is formed like those of other quadrupeds. — B. 
2' See B. xxxii. c. 52. 
Pliny, speaking of the different kinds of frogs,. B. xxxii. c. 18, says, 
" There are some which live only in the hedges, and thence have the name 
of rubeta, or bramble frogs." It seems impossible to identify this reptile 
with any of oar known animals : and we may conclude that there is no 
foundation for the statement. JSlian gives an account of the venomous 
nature of tbis animal. Anim. Nat. B. xvii. c. 12. — B, 
39 As Cuvier remarks, it is impossible that any animal can discharge by 
vomiting what Pliny terms the " coagulum," which is the fourth stomach 
of a ruminant animal; the same substance which, under the name of 
rennet, is employed to coagulate milk. He conjectures, that the error may 
have originated in the observation, that occasionally in fish, when suddenly 
drawn out of the water, the air-bladder is protruded from the mouth, 
which may have been mistaken for the stomach. The circumstance is 
mentioned by Aristotle, Hist. Anim. B. viii. c. 23, and by ^lian, Anim. 
Nat. B. iii. c. 19, as well as the vomiting of the bile ; respecting this 
latter, we may remark, that vomiting is produced in various animals, when 
under the influence of extreme terror. — B. 
