TACTILE RESPONSES OF DE-EYED HAMLET 165 
carrying the intact eye pressed against the confining wall. They 
seldom, if ever, moved in any way as the result of a solid object 
being brought near them on the blind side, although when actu- 
ally touched on that side, however lightly, they made exceed- 
ingly violent escaping movements—much more vigorous move- 
ments, in fact, than are ordinarily evidenced by the normal 
seeing fish. 
Whether or not the delicate form of sensitivity described for 
the completely blinded hamlet is present and actively functional 
in the unblinded animal cannot be decided from the facts so far 
given; but it can be shown that the responses in question are 
not the result of special sensory alterations determined by or 
during anaesthesia, since 1) different anaesthetics (chloroform, 
ether, chloretone) and various degrees of narcosis could be used 
for the de-eying operation without affecting the result in any way; 
2) there is no discernible increase in sensitivity after a fish pre- 
viously de-eyed has recovered from a second anaesthetization ; 
3) a non-de-eyed fish does not give responses of the character 
under discussion after recovery from (chloretone) anaesthesia; 
4) several hamlets from which the eyes were removed without 
anaesthesia, gave well-defined reactions of this nature. 
Inasmuch as the reactions to the careful approximation of solid 
bodies were secured very shortly after the operation, and were 
evident almost to their maximal extent within twenty-four 
hours, it is doubtful if the mere absence of the eyes has produced 
this form of sensitivity; the following results, as well as the 
studies upon normal individuals, support such a conclusion: 
a) When the eyes of a medium-sized hamlet were covered by a 
eap of black velvet, the fish became very restless (owing to me- 
chanical irritation of the harness required to fasten the cap); 
but after about ten hours, good ‘avoiding reactions’ were ob- 
tained upon the careful approach of a glass rod, both at the 
snout and at the caudal peduncle. 
b) In several hamlets the cornea of either eye, or of both 
eyes, was rendered opaque by searing with a hot iron. The 
fishes so treated behaved respectively as did those with one or 
both eyes removed. 
