6 CETACEA. / 
Physeteridze, Gray, Ann. Phil. 1828; Selys Longchamps, 1842. 
Cete hydrzoglossi § B, Wagler, N. S. amp. 33, 1830. 
Cetaces, Lesson, N. Tab. Reg. Anim. 197, 1842. 
Cetacea, Rafin. Anal. Nat. 60, 1815. 
Ruderer Wale, Oken, Lehrb. Nat. 661, 1815. 
Balenidia, Rafinesg. Anal. Nat. 61, 1815. : 
Balenide, Gray, Ann. Phil. 1828; Zool. Erebus and Terror,15; 
Cat. Mam. B.M.; Selys Longchamps, 1842. 
Vermivora, Lesson, N. Tab. Reg. Anim. 291. 
Baloena, Lesson, N. Tab. Reg. Anim. 201. 
Bale, Oken, Lehrb. Naturg. 663, 1815. 
4 
The Baleen or Whalebone has generally been considered as the | 
teeth of the whale; but this must be a mistake, for Mr. Knox — 
observes—“ In the foetal B. Mysticetus sixty to seventy dental — 
pulps were found on each side of each jaw, making the whole — 
number amount to from 260 to 300. The preparation (n. 56) | 
exhibits a portion of this gum with twelve pulps; had these pulps 
been confined to the upper jaw and corresponded to the number 
of baleen plates, it would have formed a strong analogy between — 
the baleen and teeth; but the number of baleen plates in the ~ 
whale greatly exceeds the number of dental pulps, and the lower 
jaw, which contained an equal number of pulps with the upper, 
has neither teeth nor baleen im the adult whale. Their presence — 
therefore in the foetal Mysticetus forms one of the most beautiful : 
illustrations of the unity of organization in the animal ceconomy. — 
The teeth in the Balena never cut the gum, but become gradually 
reabsorbed into the system; the very cavity in which the germs 
were lodged disappear; whilst to suit the purposes of nature, — 
the integumentary system furnishes the baleen, which is evidently © 
a modified form of hair and cuticle.”’—Knoz, Cat. Whales, 22. 
Professor Eschricht has shown also that the foetus of Megaptera 
Boops (Danish Trans. 1845, xi. t. 4) has numerous teeth on the - 
edge of the jaw, though they are never developed. I am inclined — 
to regard the baleen as a peculiar development of hair in the 
palates of these animals, and somewhat analogous to the hair» 
found in the palates of the genus Lepus. 
From the examination I have been able to make of the baleen - 
of Balenoptera rostrata, and of different masses of small blades 
of Balena australis, it would appear as if there was, at least in 
those two species, two series of baleen on each side of the palate ; 
the external series being formed of large triangular blades placed 
at a certain distance apart; and the internal, m Balenoptera 
rostrata, formed of smaller, much thinner, triangular pieces, placed 
much closer together and forming a very dense screening appa- 
ratus; and in Balena australis the mner series is formed of nu- 
