DIGESTIVE ENZYMES IN POIKILOTHERMAL, VERTEBEATES 
191 
Table 5. — Ereptic digestion in different groups of vertebrates 
[Digests = 12.6c. c. extract of intestinal mucosa + 2 grams casein + distilled water + 0.2 N sodium carbonate to approximately pH 
8.4 + toluol (10 per cent of total) + distilled water to 60 c. c. Controls have 20 c. c. coagulated egg albumin substituted 
for casein] 
Animal 
Aver- 
age 
tem- 
pera- 
ture 
in de- 
grees 
Milligrams tyrosine in 2 c. c. tiltrate 
Days 
Net 
gain 
C. c. 0.2 N amino acid in 10 c. c. 
filtrate 
Days 
Net 
gain 
Fish: 
Carp, to first bend /control 
of intestine \experiment. 
Carp, middle of in-/control 
testine _ \experiment. 
Carp, posterior re-/control 
gion of intestine.leiperiment. 
(control 
Pickerel.- -{experiment. 
lexperiment. 
(control 
Amphibia: Necturus -■{experiment 
[experiment. 
Reptile: 
(control 
Snapping turtle--'{experiment. 
lexperiment. 
(control 
Bull snake •{experiment 
lexperiment 
Mammal: Dog- te?^ent: 
0.087 
.097 
.067 
.073 
.057 
.057 
.073 
.067 
.057 
.057 
.059 
.074 
. 100 
. 173 
. 156 
.057 
.057 
.071 
. 112 
.112 
0.087 
.238 
.067 
.200 
.057 
. 190 
.073 
.200 
. 173 
.057 
. 182 
. 196 
. 105 
.532 
.524 
.057 
.103 
0.087 
.271 
.067 
.205 
.057 
.267 
.073 
.325 
.313 
.057 
.235 
. 105 
.633 
.851 
.057 
. 125 
.112 
.222 
. 112 
.282 
0.087 
.402 
.067 
.285 
.0.57 
.254 
.080 
. 541 
.455 
.057 
.334 
.313 
. 105 
.892 
.943 
.057 
.200 
.294 
. 112 
.334 
0.087 
. 513 
.067 
.334 
.057 
315 
. Ill 
.057 
.476 
.385 
.105 
.985 
.057 
.313 
.371 
. 112 
.392 
0.000 
.416 
.000 
.261 
.000 
.258 
.038 
.842 
.695 
.000 
.317 
.311 
.005 
.812 
.824 
.000 
.256 
.300 
.000 
.280 
0. 10 
. 10 
. 15 
. 15 
. 10 
. 10 
. 15 
. 10 
. 15 
. 10 
.10 
. 10 
. 15 
.20 
.25 
. 10 
. 10 
. 10 
.30 
.30 
0. 15 
.35 
. 15 
.20 
.10 
Vis 
. 10 
0. 15 
.50 
. 15 
.35 
.10 
.25 
.35 
.40 
.10 
.50 
. 15 
.70 
.95 
. 10 
.30 
0. 15 
.70 
. 15 
.40 
.10 
.65 
.70 
.10 
.80 
.80 
1. 10 
. 10 
.40 
.50 
.30 
0. 15 
1. 10 
. 15 
.65 
.10 
.50 
.30 
1. 20 
1.30 
. 10 
1.00 
1.00 
.20 
1. 35 
1. 70 
. 10 
.70 
.70 
.30 
1. 30 
0.05 
1.00 
.00 
.50 
.00 
.40 
. 15 
1. 10 
1. 15 
.00 
.90 
.90 
.05 
1. 15 
1. 45 
.00 
.60 
.60 
.00 
1.00 
Table 6. — Ereptic digestion at room temperature and at 37° C. 
[Digests were prepared exactly as in Table 5, with an initial pH approximately 8.4] 
Animal 
Fish: 
Carp 
Pickerel- --- 
Amphibia: Necturus 
Reptile: 
Snapping turtle.. 
Bull snake 
Do 
Mammal: Dog 
Tem- 
pera- 
ture 
in de- 
grees 
Milligrams tyrosine in 2 c. c. filtrate 
0.073 
.073 
.057 
.057 
.074 
. 074 
. 089 
.089 
.071 
.071 
.057 
.057 
. 112 
. 112 
Days 
0.200 
.222 
. 163 
.371 
. 196 
.334 
.149 
.204 
. 103 
. 154 
.222 
.267 
0.205 
.229 
.313 
.444 
.209 
.385 
. 125 
.211 
.282 
.385 
0.285 
.417 
.455 
.667 
.313 
.500 
.325 
.667 
.294 
. 556 
.200 
.357 
.334 
.500 
0.334 
.448 
.752 
.385 
.656 
. 508 
.851 
.371 
.667 
.313 
. 541 
.392 
.654 
Net 
gain 
0.261 
.375 
.695 
.839 
.311 
.482 
.419 
.762 
.300 
.696 
.256 
.484 
.280 
.542 
C. c. 0.2 N amino acid in 10 c. c. 
filtrate 
Days 
0. 15 
. 15 
. 15 
. 15 
. 10 
. 10 
.20 
.20 
. 10 
. 10 
. 10 
. 10 
.30 
.30 
0.20 
.30 
.40 
.76 
0.35 
.40 
.70 
.30 
.60 
.30 
.45 
.55 
1.00 
0.40 
.75 
.70 
1. 25 
.80 
L20 
.50 
LOS 
.50 
1. 10 
.40 
.70 
.80 
L50 
0. 65 
1.05 
1.30 
1. 50 
LOO 
L 45 
LOO 
L 40 
.70 
1. 50 
.70 
L 00 
L 30 
L 80 
Net 
gain 
0.50 
.90 
L 15 
L40 
.90 
L 35 
.80 
L20 
.60 
L 40 
.60 
.90 
LOO 
L50 
The series of parallel experiments at room temperature and at 37° C. shows 
that in all cases the rate of digestion was much more rapid at 37° C. than at 19 to 
23° C. For all the animals the increase in rate of digestion at the higher tempera- 
