366 MANTON COPELAND 
hidden food. Four puffers were isolated in an aquarium, and 
their normal reactions to the two packets were first recorded. As 
in previous experiments, fresh dogfish meat was always used for 
food, and the positions of the baited and unbaited packets were 
exchanged every fifteen minutes. During the first test hour, 
when the fish were very hungry, the packet with meat was bitten 
119 times, and the cheese cloth packet 18 times. At the end of 
the experiment the fish were fed, and three days later they were 
again tested for an hour: 67 bites at the baited packet, and 8 at 
the other one resulted. It now became necessary to eliminate the 
olfactory organs, to repeat the tests with the packets, and com- 
pare the results with those set forth above. To render function- 
less the olfactory apparatus of Spheroides was a comparatively 
easy task, involving no cutting of nerves or stitching together 
of nares. A silk thread, tied by a single knot around each organ, 
contracted the olfactory chambers so as to prevent effectually any 
flow of water through them. 
About two hours after the close of the test last described, the 
nasal organs of the four puffers were tied in this manner. An 
hour later they were snapping small pieces of dogfish meat from 
the end of a wire in perfectly normal fashion, and soon afterward 
I tested them for an hour with the two packets. At no time did 
they pay any attention to either, although they eagerly seized 
small pieces of meat dropped into the aquarium, or offered to them 
on the end of a wire. Eighteen hours later the test was repeated 
with similar results. As the packets were being suspended in 
the aquarium, the one containing cheese cloth was bitten twice by 
one of the fish, an evident visual reaction, but at no other time 
during the hour was either touched. The fish swam about in a 
characteristic manner, and, on being tested with meat fragments, 
showed they were hungry. There was nothing in their behavior 
to indicate that the contracted state of their olfactory organs was 
in itself at all disturbing. At the conclusion of the test the threads 
were removed, and, as might be expected, the nasal organs 
appeared considerably distorted. On the following day the fish 
failed to react to the packets. Two days later, however, after 
sufficient time had elapsed for the recovery of the injured parts, 
