R. R. Bensley 151 
processes would be delayed in the mucous membrane of such a saccule, 
and that its mucosa would still contain fundus glands long after those 
of the adjacent portion of the stomach had been converted into cardiac 
glands. Individuals possessing such saccular diverticula would have a 
higher digestive potential, and thus a greater chance of survival and of 
propagation than others less favored. 
There would thus be for a time a tendency to preserve and perfect 
by natural selection these saccules. Ultimately, however, the degen- 
erative processes would extend even to the mucous membrane of the 
saccule and their glands would be first converted into cardiac glands 
and finally disappear. 
We are thus furnished with a means of explaining the retention of 
cardiac glands in the large pointed sac of Bradypus, in the first chamber 
of the stomach of the peccary, and in the water cells of the camel and 
llama, while they have disappeared from the rumen, reticulum, and 
omasum, of the higher ruminants. The cells of the reticulum do not 
contain cardiac glands because they are not primary diverticula of the 
rumen. Cordier has produced evidence to show that the partition walls 
between the cells of the reticulum are produced by fusion of rows of 
vascular papille, such as occur in the rumen. 
In the anteaters, Manis, and Echidna and the duck-bill, the mechan- 
ical factor has been introduced in all probability by the admixture of 
small stones, grains of sand, ete., with the food. 
The interpretation of the glands of the water-cells of the camel’s 
stomach and of the pointed sac of the stomach of Bradypus as cardiac 
glands which have been retained long after the glands in the walls of 
the main cavity of the stomach have disappeared, because of the fact 
that they have been somewhat removed from the direct action, friction, 
pressure, etc., of the food, suggests a very interesting field of specula- 
tion as to the mode of production of the division into chambers of the 
stomach of ruminants and some allied changes in form of the stomachs 
of other mammals. The purpose of specialization of this character is 
usually conceded to be the provision of storage chambers of sufficient 
capacity to accommodate the greatly increased bulk of food of reduced 
nutritive value, and in which the preponderating carbohydrate element 
may be subjected for a longer period to the amylolytic action of the 
saliva. That the first of these considerations is of the greatest import- 
ance in determining the progressive specialization of the herbivorous 
stomach there can be little doubt. The precise way in which it acts 
however is extremely obscure. Moreover, leaving out of consideration 
the question of the prolonging of carbohydrate digestion, it is not clear 
