of the Cavities which constitute the Stomach of the Whale. gg 
stomach, is the cavity in which chyle is formed, and the 
upper or plicated portion is only to prepare the food, and is 
therefore analogous to the second in the whale. 
As the same appearances are met with in the fourth stomach 
of the bullock, as well as in the camel, although there is no 
permanent contraction, or division between them, the upper 
or plicated portion must be considered as a preparatory organ, 
and the lower portion as that, in which the formation of chyle 
is compleated. This receives further confirmation from a 
more attentive examination of the parts, immediately after 
death, by which it was found that before the stomach has been 
disturbed there is an evident muscular contraction between 
the plicated and lower portion. This appearance was met with 
in every instance that was examined, and these were not fewer 
than nine or ten. Added to this the lower portion, on a more 
minute inspection, has an appearance somewhat similar to the 
inner membrane of the human stomach : and the surface of 
the plicae is in many respects different. 
From the facts and observations which have been stated, it 
appears that in many animals of the class Mammalia, the food 
undergoes different changes preparatory to its being con- 
verted into chyle, and this last process is effected by a some- 
what similar secretion, since the part of the stomach which 
produces it, has in all of them an evident similarity of 
structure. 
The above facts appear to throw some light on the diges- 
tion of the different kinds of food, and open a wide field of 
enquiry into one of the most interesting parts of the animal 
ceconomy, which has been hitherto too much neglected. In 
the present very limited state of our knowledge there are 
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