676 DAVID HILT TENNENT. 
Twenty-four hours after the first feeding I examined the 
stomach and intestine of one specimen of each species. No 
Gasterostoma of sufficient size for observation with a hand 
lens were present, but in washings from the intestine many 
small Gasterostoma identical to those from the Silverside 
were seen. ‘The encapsuled forms had disappeared. 
Twenty-four hours later I again made a similar examina- 
tion with similar results. Two days later the results were 
the same. 
Three days later (at the end of one week’s time) I made 
the last examination. Unfortunately, by the breaking of an 
aquarium, one set of experiment fishes had been lost. In 
the three remaining species small Gasterostoma were found 
in abundance. On this occasion it was possible to notice a 
difference in the size of the Gasterostoma present. Some 
had nearly doubled in size. 
It is interesting to note that, even in the short time during 
which the experiments had been conducted, the Gasterostoma 
had grown to a greater size in the perch and the black bass 
than in the pin-fish. 
The experiment should have been continued for a longer 
time, for a month at least, but the time during which I could 
stay at Beaufort had passed, and it became necessary to 
discontinue the work. 
Sufficient had been shown by the experiment to convince 
me that the Gasterostoma found in the Silverside could 
resist the action of the digestive juices of other fish. There 
were present in the intestine of the gar many specimens only 
slightly different in appearance, chiefly in size and sexual 
maturity, from those which I obtained at the end of the week 
from the experiment fishes. 
Since I had already determined that the Silverside was 
one of the gar’s sources of food I could but naturally 
conclude that it was also its source of Gasterostoma. 
How and where the Silverside obtains its cercarie I do 
not know. The food of the Silverside consists chiefly of 
small crustacea. An examination of many of these failed to 
