1901} MICROSCOPICAL JOURNAL. 277 
weight as ballast to counteract the natural buoyancy of 
the body, like the stones of considerable size usually 
found in the stomachs of alligators, and which are sup- 
posed to have been swallowed to assist them in remain- 
ing at the bottom. 
The fact that there were no grains of black sand among 
it, which does not polarize, would rather seem to lend 
support to the digestive theory; inasmuch as white sand, 
being composed of quartz, or almost pure silica, and hard 
enough to scratch glass, would naturally be selected by 
them to assist in the grinding or trituration of their food, 
rather than the much softer black sand. 
There was observed at one place an agglomeration of 
small, round grains, quite smooth outside, like very small 
fish eggs, which they perhaps were, or spores of some 
‘small toadstool or other fungus. They were transparent, 
and not much over one-quarter the size of the grains of 
sand mentioned above. 
A great quantity of some dark-colored substance, finely 
comminuted and apparently of animal origin, was found, 
perhaps the remains of worms or meat of some kind; but, 
although most carefully sought, for, there were no feet, 
wings, scales of lepidoptera, parts of insects, crustaceans, 
or muscular fibers of any sort among it, such as would 
have been likely to have survived the digestive process 
and given a clew to its character, | 
As we may see from the smallness and degree of con- 
_ vexity of their eyes that fish must be capable of seeing 
things infinitely smaller than would be visible to the 
human eye, this matter was perhaps composed of minute 
particles of both animal and vegetable origin which the 
fish met with and swallowed as it swam about, and which 
were perhaps too small to preserve any definite recogniz- 
able character, especially after passing through the stom- 
ach. 
Their principal food, though, to judge from the great 
