On the Anatomy of Balenoptera rostrata. 299 
. ‘Two equal lengths of the.dried tendons were then weighed and 
_ found to be im the proportion. of 845 to 495, which was assumed. to 
be the proportion of their cross sections. The smaller of these 
numbers is 59 per cent. of the greater—a result that seems to be 
as near to the former result derived from the muscles as can be 
expected in this class of experiments. 
“Qn the Anatomy of Balenoptera rostrata, Fab.” By Avex- 
ANDER Carte, M.A., M.D., &c., and ALEXANDER MACALISTER, 
M.D. &c. 3 et 
In this paper the authors give an account of the dissection of a 
young female of the Lesser Fin or Piked Whale, which was cap- 
tured off Clougher Head, co. Louth, Ireland, on the 8th of May 
1863. | : 
After describing its external form, and giving accurate measure- 
ments of its various parts, the authors point out some differences 
between the relative sizes and positions of the organs of the-animal 
as contrasted with similar parts of those of the same species. which 
have been recorded by previous writers, especially as regards the 
position of the dorsal fin, which appendage seems to vary in situa- 
tion in different individuals, and show that consequently no value, 
as indicative of species, ought to be attached to its relative position. 
This is followed by a description of the osteology of the animal ; 
and attention is drawn to the fact that the body of the axis vertebra 
is composed, in part, by the displaced body of the atlas, showing 
that what at present forms the upper half of the centrum of the 
axis is in reality the centrum of the atlas. 
The myology of the different regions of the animal has been 
closely investigated, especially the rudimentary muscles of the 
paddle, which latter:the authors have minutely examined. 
. The anatomy of the mouth, pharynx, and blowholes is described, 
and the mechanism by which the functions of respiration and 
deglutition are performed. In connexion with the larynx, a re- 
markable muscular pouch is mentioned as existing, which ap- 
pendage is supposed by the authors to be accessory to the act 
of expiration, serving a somewhat similar office to that of the 
air-reservoir in a double-action bellows. Directly in front of the 
glottis there existed a peculiar hood-like fold of mucous membrane 
arranged in such a way as to allow of its being drawn over the 
orifice, and so prevent the entrance of all foreign substances into 
the respiratory tract during the act of deglutition. 
The tongue was found fixed, as far as its tip, by.a thick fre- 
num. The lateral walls of the submaxillary cavity were thrown 
into folds, thereby admitting of considerable distention, this ar- 
rangement being peculiarly adapted to the feeding-requirements 
of the animal. The number of baleen plates found in the speci- 
- men was 280 on each side. : 
The muscles for acting on the blowholes were arranged in 
three strata, the superficial and deepest. layers being used in 
opening, and the intermediate one for closing the nasal canals.. 
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