Sidney Klein 329 
It seems clear from these facts that the cells of Paneth are specific 
elements engaged in the secretion of a special substance, probably an 
enzyme which is of use in digestion. It is not, however, possible to con- 
nect the Paneth cells with the formation of the new substances, secretin, 
erepsin, and enterokinase, because these substances are also found in the 
small intestine of carnivora in which Paneth cells do not occur. Nor is 
it possible to connect them definitely with any particular class of food, 
as Moller suggests, because they have been found not only in herbivorous 
and granivorous animals, but also in insectivora. 
In conclusion, I wish to express my indebtedness to Professor Bensley, 
at whose suggestion and under whose direction the work was undertaken, 
for friendly guidance and advice during the progress of the investigation. 
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