no 
ANATOMY AND PHYSIOLOGY 
a respiratory organ, and when it contains the organ of 
smell (as in the whalebone whales), that is only se- 
condary. As the animals of this order do not live in the 
medium which they inspire, the organs conducting the 
air to the lungs are, in some sort, particularly constructed, 
that the water in which they live may not interfere with 
the air they breathe. The beginning of the posterior 
nostril, which answers to the palatum molle in the quad- 
ruped, having a sphincter, the glottis is grasped by it, 
which renders its situation still more secure, and the 
passages through the head , across the fauces , and along 
the trachea , are rendered one continued canal . 
This union of glottis and epiglottis with the posterior 
nostril, making only a kind of joint , admits of motion 
and of dilatation and contraction of the fauces in deglu- 
tition , from the epiglottis moving in or out of the poste- 
rior nostril. This construction of parts answers a 
purpose similar to that of the epiglottis in the quadru- 
ped; it may be considered as the epiglottis and the 
arytasnoid cartilages joining to make a tubular or cylin- 
drical epiglottis, instead of a valvular one. The reason 
why there should be so peculiar a construction of parts 
does not at first appear, but we certainly see by it an 
absolute guard placed upon the lungs, that no water 
should get into them 
OF THE BRAIN. 
“ The size of the brain differs much in different genera 
of this tribe, and likewise in the proportion it bears to 
