586 POPULAR LECTURE ON THE PREVAILING EPIZOOTIC 
very extraordinary cases of disease or injury. In ruminants, the 
process of digesting the food is very different from that in the 
horse. In the cow, when the food is gathered by the mouth 
and swallowed, it goes into the paunch. The animal having 
eaten enough, allows the food to remain a sufficient length of 
time in the paunch to undergo a certain change like maceration, 
by the heat and juice of this cavity; and then the food passes 
from the paunch into another cavity called the second stomach. 
From the second stomach the food is forced up in small pellets 
back to the mouth, where it undergoes a second chewing (called 
“ rumination” or “ chewing the cud”). In this second chewing, 
each pellet is ground into a soft pultaceous mass, and mixed with 
a large quantity of saliva. The animal then swallows the morsel 
for a second time : but, instead of returning to the cavity or 
stomach to which it went on the first swallowing, it now passes 
by its entrance, without getting admission, and on leaving the 
gullet, goes immediately into a third stomach. This third stomach 
is so peculiarly formed, that it will not admit the entrance of any 
solid food that has not been previously ground down to extremely 
small particles by the process of the second mastication. It has 
within it a number of membraneous folds, resembling in their 
arrangement the leaves of a book. The leaves of the third sto- 
mach being rough on their surface, and endowed with a rubbing 
motion between each other, the food in passing between their 
surfaces undergoes a still further rubbing down. Not until it 
has passed through this stomach does it enter the membraneous 
cavity or sac which corresponds with the horse’s single stomach. 
The first and second stomach of the ox may be regarded merely 
as receptacles for the collected food to macerate in previous to 
rumination, or its being a second time masticated. Every thing 
swallowed for the first time, with the exception of liquids or 
semi-liquids, goes into these stomachs ; and even liquids, when 
taken in large quantities and with rapidity, go there also. 
However, liquids, when poured down the animal’s throat by the 
hand of man, if permitted to descend in very small quantities at 
each swallow, and slowly, generally pass directly into the third 
stomach, and thence, through the fourth one, into the intestines. 
But even when the fluid does drop into the first and second sto- 
mach, it can, from its liquid nature, slowly pass into the third 
one. Solid matter cannot do so* Previous to passing from the 
paunch into the third stomach, the solid food must be regurgi- 
tated, and masticated a second time, in order to render its parti- 
cles fine enough for admission into the manyplus, whence it goes 
on being re-swallowed. A consideration of these anatomical and 
physiological facts leads us to select the following considerations 
