98 PHYSIOLOGY AT THE FARM. 



abdominal digestive cavities, of muscular fibres enclosed be- 

 tween a serous external and a mucous internal tunic the 

 muscular fibres being crossed by strong fleshy bands which 

 divide the organ into four pouches. Externally these divisions 

 are best seen when the right aspect of the paunch is examined. 

 They are, however, more easily understood when seen after 

 the paunch has been laid open, as in fig. 10. 



The first stomach is of very great size, and occupies a con- 

 siderable part of the abdominal cavity. It is lined with a 

 cuticular investment, and presents a shaggy pile, but either 

 does not secrete any fluid, or only in sparing quantity. It 

 is termed the paunch or rumen, and is merely a temporary 

 reservoir for the food. The second stomach is much smaller, 

 and its walls are covered with numerous polygonal cells, 

 which, being like the cells of the honeycomb, have gained 

 for it the name of the honeycomb or the reticulum. The 

 lining membrane of the second stomach, like that of the first, 

 is cuticular. The third stomach is the smallest of all : it has 

 its lining membrane so disposed as to form deep lamellae 

 arranged longitudinally in alternating large and small layers, 

 so as to present a most extensive surface. It is named popu- 

 larly many plies, and is also called psalterium and omasum. 

 Its lining membrane is cuticular, like that of the first and 

 second stomachs. The fourth stomach is the second in point 

 of size : it has an elongated pyriform shape, and its internal 

 membrane has all the prominent characters of the mucous 

 membrane of the stomach in man and other mammals in which 

 the organ is simple. It is commonly called the red or reid, 

 the abomasum, or the rennet. Both third and fourth stomachs 

 are seen cut open in fig. 11. 



The first stomach is of small size in the calf, and while the 

 young animal is fed on milk it does not take part in the 

 reception of the food. When it is fully developed it is divided 



