THE ALIMENTARY TRACT 195 
attempt at adjustment between the food, the methods of 
mastication, the area of digestive surface, and the bulk 
necessary for nutrition. The number of factors opened 
up by the many variations between this complex tract and 
that of the carnivorous simple tract is so great that I shall 
attempt only to contrast the anatomy and pathology of 
the simpler ungulate tracts and the complex rumi- 
nant apparatus. 
The simpler gastrointestinal tract is possessed by the 
Perissodactyla, and by the follo^ving families of Artio- 
dactyla, the Pliachocoerid£e, Suidae and Tayassuidae. This 
consists of a stomach with a single cavity (some Peccaries 
have partitions but no true septa with strict histological 
differences) divided into esophageal, cardiac, fundal and 
pyloric areas, dependent upon the nature of the lining 
epithelia and the absence or presence of glands, as well as 
the nature of the tubules. The duodenal section is ample 
and may be sacculated while the intestines are small in 
calibre and rather sturdy in wall. The cecum is rela- 
tively very large, well supplied by longitudinal bands and 
sacculations; the colon is relatively short but quite 
capacious and sacculated. 
The ruminants and other remaining members of the 
Artiodactyla have a compound stomach suited to the 
separation of coarse and fluid foods and the retention of 
water, and so arranged that boluses of different densities 
are distributed as needed. These divisions are histo- 
logically as well as grossly different. The first three, 
comparable to the esophageal section of the simpler 
stomach, are reservoirs or channels, while the fourth or 
true digestive section, is divided into areas corresponding 
to fundus and pylorus, possessing the appropriate type 
of gland. The duodenum in this group is narrow, as is 
the rest of the small gut, and has delicate walls. The 
cecum proper is short and of variable width, but never as 
great as in the group first discussed, while the colon, an 
intricately wound tube, is narrow and very long. Certain 
