440 ALFRED O. GROSS 
I have found. WTien the above gangUon is removed, the animal 
is less sensitive to chemicals, because that part of the chemical 
sense which resides in the palps and tentacles is lost. The 
nerves of the tentacular cirri were left intact, as evidenced by 
the fact that the cirri were still responsive to mechanical stimula- 
tion. Unfortunately, Maxwell's experiments are of less value 
from the standpoint of their bearing on the sense of taste because 
his observations, as before noted, are not of the feeding reactions 
of Nereis. The responses he secured bj^ holding a piece of worm 
flesh in front of Nereis was merely the characteristic defensive 
thrust, due to chemical stimulation or irritation. These 
responses are, at best, very irregular and erratic and cannot be 
used in careful comparative work. In the tests on the operated 
worms Maxwell placed the stimulating substances, i.e., pieces 
of worm flesh in the sea-water containing the Nereis. Under 
such conditions it is difficult to detect and impossible to meas- 
ure quantitatively the effect of chemical stimulation on the 
worm. To such a liquid the worms soon became adapted and 
not stimulated at all. That the operated worms exhibited no 
feeding reactions under these conditions is perfectly obvious, 
because even a normal Nereis does not feed upon flesh, with 
which Maxwell tested the worms. I have found that worms 
still respond to chemical stimulation after the brain is removed 
if tested by the method previously described. This chemical 
sense of the general integument evidently works through a 
ganglionic reflex, that is, through the ganglia of the ventral 
nerve cord. 
In addition to the rich innervation of the palps and tentacles, 
as shown by Retzius, there is an abundance of diffuse integu- 
mentary sense organs to be found on these appendages. Lang- 
don has shown these organs to be especially numerous on the 
tentacles and on the tips of the palps. But since these organs 
are also abundant on the tentacular, parapodial, and anal cirri, 
their significance in connection with the sense of taste is at 
least a doubtful one. From the standpoint of distribution, 
the evidence is to the contrary, and I am inclined to believe 
these integumentory sense organs, which are also abundant 
