242 
DES. A. CAETE AND A. MACALISTEE ON THE 
condensed halitus from the lungs being suddenly and forcibly driven upwards, may 
simulate a column of water ; but that a large quantity of ingested fluid is got rid of by 
the act of expiration through the blowholes is, at least in the present instance, not only 
improbable, but in fact impossible, as from the mechanism of the organs engaged there 
was no contrivance by which the entrance of the fluid from the larynx, if present, into 
the lungs or digestive canal could be prevented ; the only appearance of a receptive 
cavity in connexion with the respiratory tract was the large laryngeal pouch before 
described, but from the position of the opening of this sac into the cavity of the larynx, 
any fluid admitted into it must necessarily enter the lungs and so suffocate the animal. 
Expiration having been accomplished, the animal now protrudes its blowholes above 
the surface of the water ; the abdominal muscles are relaxed, and the diaphragm 
descends ; the nares at the same time being opened, a stream of air enters the lungs 
through the larynx, the apex of which is still retained in the orifice of the posterior 
nares ; the thorax is likewise expanded by the action of the serrati, intercostales, and 
pectoral muscles, and when the act of inspiration is accomplished the larynx descends, 
the middle plane of muscles closes the nares, and aeration of the blood, by means of the 
inhaled air, is carried on. In other cetaceans the process of respiration is effected in a 
manner somewhat similar, though the anatomical arrangements admit of individual 
varieties. In Glohiocephalus Svineml there was developed a special muscle, the basio- 
thyrohyoid, which arose tendinous from a longitudinal antero-posterior line on the 
basilar process of the occipital bone, and was inserted into the posterior border of the 
thyroid cartilage, and into the posterior cornu on the basihyoid bone ; this muscle seems 
to be developed for the purpose of drawing the larynx upwards, and so compressing the 
pharynx against the spine, and preventing the possibility of the entrance of air into 
the digestive canal. In this animal likewise the superior constrictor of the pharynx 
arose from the anterior edge of the internal pterygoid plate, about 3 inches within the 
openings of the posterior nares, from whence the fibres ran inwards and backwards to 
the median line of the pharynx, which it forcibly draws forwards. These additional 
arrangements facilitated the drawing upwards of the larynx. 
The act of deglutition appears to be more simply performed ; the animal, according 
to Lilljeborg and others, subsists chiefly on fish, together with mollusca and medusae ; 
in the stomach of our specimen nothing was found but the crystalline lens of the eye of 
some small fish. 
The mode of taking food appears to be as follows : — the mouth is opened under water, 
and with the relaxed submaxillary pouch encloses a quantity of animals and fluid together, 
while at the same time the palatoglossus being contracted, shuts off all communication 
with the pharynx ; the mouth is now closed, and the pouch contracted by the action of 
the mylohyoid or constrictor muscle aided by the elasticity of the pouch itself; these 
together exert a force sufficient to expel all the superfluous water, while the baleen 
plates prevent the escape of all solid matters, which being strained are left in a 
condition fit to be swallowed: the palatoglossus now relaxes, and the tongue being 
