M. E. Jewell and H. B. Lewis 165 
TABLE II. 
Vertebrates in Which the Absence of Lichenase Was Uniformiy Demon- 
strated with Organ or Tissue Investigated. 
Class. Species. Organ. 
Pisces. Gold fish. Alimentary canal. 
Amphibia. Frog (adult and tadpole). . ce 
Reptilia. Horned toad.* os + 
, Garter snake. ip os 
a! Turtle (two species). Pancreas, upper portion of 
small intestine. 
Aves. Domestic fowl. oe 43 
Mammalia. Rabbit. + : y 
ia Pig. Pancreas. . 
a o Sheep. Small intestine. 
- Dog. Pancreas. 
Man. Saliva. 
* Obtained through the courtesy of Professor A. O. Weese, of the Uni- 
versity of New Mexico. 
rence of these two enzymes in the organism of the invertebrates 
studied. 
One other point in connection with the presence of enzymes 
other than lichenase is of interest. In the hepatopancreas of 
the two chitons (Nos. 7, 8, Table I) sucrase was absent. Since 
this enzyme is so widespread in its distribution examinations 
were made repeatedly on.these species with the same negative 
results as far as sucrase was concerned. Of the sixteen species of 
invertebrates examined for this enzyme, these were the only 
two in which the presence of sucrase could not be demonstrated. 
It was realized that with the preservative used, toluene, bac- 
terial action was not necessarily completely inhibited. In view, 
however, of the uniformity of the results, positive with inverte- 
brates, and negative with vertebrates, hydrolysis of the lichenin 
can hardly be ascribed to the action of the bacteria, since if bac- 
terial enzymes are concerned there is no reason why vertebrate 
extracts should not be contaminated with bacteria as frequently 
as invertebrate extracts. Moreover, it would be difficult to 
understand why inulin or raffinose should not be attacked as 
well as lichenin since many strains of Bacillus coli, one of the pre- 
vailing types of organisms of the alimentary tract, ferment 
