TACTILE RESPONSES OF DE-EYED HAMLET 169 
clusive evidence for this belief cannot be adduced. The higher 
sensitivity of the anterior end of the de-eyed hamlet was not 
occasioned by the presence of freshly exposed tissue surfaces in 
the orbits or by other injuries, since in several cases the animals 
were kept in aquaria for more than four months, long after the 
orbit surfaces had cleanly healed, and their reactions were as 
distinct as those of recently de-eyed fishes. 
The relatively acute sensitivity of the region behind each 
pectoral fin, as judged by the reactions obtained when it was 
approached by a rod, is probably a secondary condition, due to 
the fact that the pectoral fins are usually in slight motion, creat- 
ing in the water waves which impinge upon thgse surfaces; any 
disturbance of these wave fronts or fin currents would result 
in a greater stimulus than that afforded by the near approach 
of a rod or wire to a stationary part. 
3. I have ventured to describe these tactile reactions of the 
de-eyed hamlet at some length, because the fine, ‘epicritic’ nature 
of the sensitivity evidenced toward minute mechanical disturb- 
ances in the water is of particular use for the purposes of cer- 
tain critical experiments regarding chemical stimulation of the 
skin of fishes. It will be observed that crude tests made by 
applying solutions from a pipette to the skin of Epinephelus 
would be quite pointless, since the blinded fish reacts with pre- 
cision to the presence of the undischarged pipette. The degree 
of sensitivity in these delicate tactile reactions is nevertheless 
rather definitely fixed at a uniform level, as seen in the more than 
twenty-five individuals I have examined. The speed, vigor, 
and amplitude of these reactions give them a perfectly definite 
character. It is conceivable that this tactile sensitivity might 
be enhanced or diminished under various conditions and that 
such variations would be reflected in the behavior of the de-eyed 
fishes, and that, in fact, a good opportunity would be offered 
for discovering the way in which tactile terminals may be influenced 
by such treatment of the skin as is involved in the local applica- 
tion of chemical excitants. If, as is supposed by Coghill (14, 
p. 197; ’16, p. 302), those responses of fishes and amphibians 
usually regarded as being initiated through excitation of ter- 
