186 M. F. Cuvier De I'Histoirc Naturelle des Cetaces, 
the remaining pages of the volume. The author's description of the 
Chachalot the Physeterae or sperm whale, is imperfect, as it could 
scarcely fail to be ; and more especially as Mr Beale's valuable pam- 
phlet had not reached his hand till after his treatise had well nigh 
passed through the press. Like the Baron our author reduces the 
alleged species to one only, the Macrocephalus. 
M. Cuvier numbers only three species under the genus Rorqual, es- 
tablished by his brother ; these are the Jubbarte, the Mediterranean, 
and Cape of Good Hope species, thus inaccurately rejecting the Rostra- 
tus of Fabricius. In his plate of the first of these, which, to all appear- 
ance, is an exact copy of Lacepede's IMuseau pointu> he represents a 
great pouch projecting from under the tongue; and in the introductory 
discourse, after inquiring what is the nature of this sac, he answers, 
that it still remains to be ascertained. He adds, that some have suppos- 
ed it to be connected with the respiratory apparatus, and others have 
viewed it as a swimming vessel, and, dissatisfied with these supposi- 
tions, suggests it may probably be the stomach distended after death 
by gas. But why the stomach ? As every one knows there is much 
loose cellular membrane in this part of the body ; and it is equally 
notorious that the whole of this tissue has the greatest liability to 
very rapid distension : this sac has only in one instance, we be- 
lieve, been seen in the living, but very often in the dead animal ; 
and we confess that this fact suggests an explanation which is 
alike simple and satisfactory. We are also told, in the words 
of Van Breda, that the use of furrows under the lower jaw and 
throat is also unknown. So long as the animal is observed out of its 
native element we can easily believe that no satisfactory idea could 
be formed of its use ; but when seen in water, and when it is there 
observed, that these furrows open out, and so produce an immense 
hollow bag or sac, thus supplying to the lower jaw of the Rorqual, 
that space which the Mysticetus, from its different shape, enjoys in 
the upper, then, we apprehend, that no difficulty should remain. 
If we remember right, M. J. Hunter, after examining the parts in 
the dead animal, was led to believe that these folds had no peculiar 
pliability, and that they could never relax and open out in the man- 
ner we have just mentioned: but, we know it is not less true that, 
having been examined in water, the augmented capacity of the 
mouth thus produced by this structure has been ascertained to be a 
fact, and its use thus demonstrated beyond a doubt. 
In our author's account of the Greenland whale he repeats the old 
tale, that it reaches the length of 80, arid even it is said, of 100 
feet. * In a note he tells us that this is contrary to Mr Scoresby's 
* P. 365 
