Digestive Organs of the Ox and Sheep. 
37 
a smooth surface, so that no additional mechaniral impediment 
should interfere with the ready passage of the aliment from one 
pouch to the other. The function of the rumen will be better 
understood when the peculiarities of the reticulum have been 
pointed out. This viscus receives its name from the net-like 
structure of its mucous membrane. It is attached to the anterior 
part of the rumen, on the left side, and lies directly under the 
terminati(m of the oesophagus. Its muscular coat is composed of 
two orders of fibres, the outer being arranged in a circular and 
the inner in a longitudinal direction, by which means the viscus 
is capable of being generally compressed. On exposing its in- 
terior, by cutting away the left side while in situ, two fleshy bands 
Fig. 5. 
The Rumen and Reticulum laid open by removino tlie left side, viiile in situ, 
a. The (Esophagus. b. The Reticulum.' c. The Anterior Pouch of the Rumen, 
d, The Middle. e, The Postero-Superior ; f. The Postero-Inf'erior, Compartments, 
g and A, The Pillars of the CEsophageal Canal. t, The Entrance to the Omasum. 
are seen leading from the termination of the oesophagus and 
winding through the cavity towards an opening which communi- 
cates with the omasum. These bands or pillars constitute the 
lateral boundaries of the oesophageal canal. (See g and h, fig. 5.) 
The muscular fibres of which they are formed run parallel with 
their course, and, when in action, they must tend to approximate 
the entrance into the omasum to the termination of the oesophagus. 
We proceed to make a few observations on the physiology of these 
two stomachs, it being generally admitted that they are chiefly 
employed in the act of rumination ; although a difference of opi- 
