of the Solvent Glands , &c. 401 
In this bird the reverse takes place of what was mentioned 
to happen in the cassowary and American ostrich, for the 
stones and other hard bodies swallowed by these birds, must, 
from their weight, force a way into the gizzard, which is a 
large cavity adapted to receive them ; but here all such sub- 
stances must remain in the cardiac cavity, both from its being 
the most depending part, and from the cavity of the gizzard 
being too small to admit of their entering it. 
The cardiac cavity contained stones of various sizes, pieces 
of iron, and halfpence; but between the grinding surfaces of 
the gizzard, there were only broken glass beads of different 
colours, and hard gravel mixed with the food. 
In taking a review of the structure of the digestive organs 
of the cassowary, the American, and African ostrich, whose 
mode of progressive motion is the same, we find their organs 
very differently circumstanced with respect to the means of 
ceconomising their food. 
The cassowary and American ostrich differ from birds that 
fly, in having the solvent glands placed in a cavity of unusual 
size and the muscular structure of the gizzard uncommonly 
weak ; the mode of progressive motion, which is a kind of run, 
producing so much agitation between the stones and the food, 
as to render a stronger muscular action unnecessary. 
In the cassowary there appear to be no considerations of 
oeconomy in the management of the food in the process of 
digestion, the solvent glands are less complex than in the 
ostrich, as is avowed by those who have examined them,* 
the food has a free passage from the gizzard into the intes- 
tines, which are unusually wide and short, so that its passage 
* Vide Pee rault’s Comp. Anat. 1676. 
