386 ELDON W. SANFORD 
necessary before fat can be digested and absorbed; in several 
eases I found the lumen full of fatty substance, but no secretion 
sacs in evidence, and therefore no absorption. This must 
mean that cells of a large region of epithelium undergo a resting 
stage at one time; the stomach may thus be actively secreting 
and absorbing while the coeca do neither, even if stuffed with 
food. Or the coeca may be active while the stomach is not. 
These observations give evidence that the stomach and coeca 
are similar in function, and that the coeca may be considered 
as expansions of the stomach which offer a large surface for 
digestive processes. It also seems clear that the enzyme which 
acts on fats in the stomach is entirely derived from the secretion 
globules of the cells. 
Jordan and others have found a fat-splitting enzyme in the 
stomach. Plateau found an emulsifying power, and Jousset 
showed the presence of an acid after the enzyme’s action. I 
have verified that the enzyme is a true lipase, which splits fats 
to fatty acids and glycerol. I will not here describe in detail 
my method of determining the lipolytic action of the stomach, 
for I used the same method as in the experiments on the crop. 
The stomachs and coeca of thirty cockroaches were extracted 
in 30 ee. of normal salt solution. Of the 30 cc. of the extract 
10 ce. were left in a flask at room temperature for seventy-two 
hours; to another portion of 10 cc. was added 10 cc. of olive oil. 
The mixture was shaken and treated like the first.. Both were 
titrated against 1/20 normal NaOH. The portion without the 
olive oil titrated against 1.0 cc. of the alkali, while the portion 
with the olive oil titrated against 7.2 ec. of the alkali. This 
showed that the equivalent acidity of 6.2 cc. of alkali had been 
produced from the olive oil, and left no doubt that a lipolytic 
action had occurred and had produced the extra acidity through 
the formation of fatty acid as a digestion product of the olive 
oil. 
The above results were obtained by using the stomachs and 
coeca together, so they did not make clear what separate parts 
the components took in the process. To determine this I dis- 
sected ten animals, removed the stomachs and coeca separately, 
