192 
BULLETIN OF THE BUREAU OF FISHERIES 
ture was in about the same proportion. It may be concluded from these experi- 
ments that erepsin like that occurring in the intestinal mucosa of mammals occurs 
in the intestinal mucosa of fishes, amphibians, and reptiles. 
CARBOHYDRATE-SPLITTING ENZYMES 
AMYLASE 
The results of all the digestion tests with carbohydrate-splitting enzymes are 
given in terms of the reducing power in milligrams of glucose per c. c. of digest. 
Table 7 shows the rate of starch digestion by extracts of esophageal and stomach 
mucosa from pickerel, bull snake, and snapping turtle, and of stomach mucosa from 
the crappie. While slight hydrolysis of starch took place in all these experiments, 
especially in the esophagus of the pickerel, its rate was too low to indicate the 
presence of amylase in sufficient quantities to be of digestive significance. 
Table 7. — Amylase 
[so c. c. digests were used containing boiled starch to 1 per cent and toluol to 5 per cent of total volume. Controls contained 
boiled extracts] 
Description 
C. c. 
of ex- 
tract 
Milligrams glucose per c. e. 
digest 
Days 
Net gain 
Days 
Iodine test 
at 2 or 4 
days 
Esophagus: 
Pickerel No. 1 
Pickerel No. 2 . 
Pickerel No. 3 - 
/control -- 
"\experiment 
/control 
"\experiment.. 
/control 
lexperiment. 
B-l'-'^e teSent: 
Snapping turtle . 
Stomach : 
Crappie 
/control - 
"\experiment.. 
/control 
"lexperiment. 
Pickerel No. 1 
Pickerel No. 2 
/control 
"\experiment_ 
/control 
"lexperiment- 
Bull snake ^l^ent: 
snapping turtle 
1. 08 
1. 08 
1. 06 
1. 06 
1.03 
1.03 
1.02 
1. 02 
1. 15 
1. 15 
1.20 
1. 20 
1. 11 
1. 11 
1.03 
1.03 
1.02 
1. 02 
1. 15 
1. 15 
1. 08 
1. 79 
1.09 
2.63 
1. 06 
2.50 
1.04 
1.21 
1.02 
1. U 
1. 11 
3. 12 
0.00 
.71 
.00 
1. 15 
1.34 
1.20 
1.43 
1. 11 
1. 17 
1.15 
1.34 
1.20 
1.69 
1. 11 
1. 30 
1.03 
1.34 
1.02 
1.09 
1.02 
1.16 
1. 15 
1. 82 
1. 20 
2. 17 
1. 11 
1.47 
0. 01 
1. 55 
.00 
1.44 
.01 
. 18 
.00 
.09 
0.03 
2.04 
.00 
. 19 
.00 
.06 
1. 02 
1. 15 
1. 15 
1. 73 
.00 
.00 
. 19 
.00 
.31 
.00 
.07 
Blue. 
Brick red. 
Blue. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
In the intestinal mucosa of representative fishes, amphibians, and reptiles, and 
in the caeca of the crappie (Table 8) a considerably larger amount of amylase was 
present. However, 2 c. c. of extract did not convert all of 50 c. c. of 1 per cent 
cooked starch in four days, a much slower rate than that of the extremely rapid 
digestion by extract from pancreatic tissues. These data indicate the presence of 
a greater amount of amylase in the intestinal mucosa of the animals whose diet in- 
cludes a considerable amount of vegetable matter, as the carp and turtle, and a less 
