100 
Mr. Home's Observations on the Structure 
many circumstances which cannot be accounted for: these 
however, will be explained when a further progress has been 
made in this investigation. 
It is obvious, that as the stomachs of carnivorous animals 
are the most simple, animal substances, on which they feed, 
require a shorter process to convert them into chyle than 
vegetables ; but why the whale tribe, which live on fish, 
should have a more complex stomach, it is not easy to ex- 
plain : since fish are very readily converted into chyle, in the 
stomachs of animals of their own class, as well as in the 
human stomach, and there is therefore reason to believe that 
they require as little preparation for that process, if not less 
than animal substances. 
The fish bones swallowed by the whale tribe being retained 
in the cuticular bag, till they are reduced to jelly, explains 
the circumstance of cows, and other ruminating animals being 
able occasionally to live on fish, (a fact, of which there is no 
doubt, both in the Orkneys and in Iceland,) since, if the bones 
are dissolved in the paunch, the other stomachs, are in no 
danger of being injured from the animal living on this kind 
of food. 
Whether these cavities, which I have called preparatory 
stomachs, are solely for purposes connected with digestion, 
or are also in any way connected with the formation of secre- 
tions peculiar to those animals, cannot be ascertained in the 
present state of our knowledge of digestion. 
The oil of the physeter, which crystallizes into spermaceti, 
shews some affinity in this respect to the secretion of fat, 
that becomes suet, which is only met with in ruminating 
animals : but on the other hand, the oil of the rest of the 
