266 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
they have also been named.” Such a condition does not occur in 
Amiurus ; but other accessory protected nerve-hillocks are present, 
of which I can find no mention in the literature of the subject, 
unless they prove to be structures similar to those described by 
Leydig in the pike and burbot. He says of the former: “In addi- 
tion to those ‘ lateral organs’ which are present along the principal 
and accessory lateral lines they are distributed also elsewhere. On 
the trunk they are arranged in rows transverse to the long axis of 
the body. Each row may be compcsed of six to ten hillocks. In 
such spots the pigment of the skin only approaches so as to form a 
sort of boundary line, and the slime cells are likewise absent, so that 
the row of sense-hillocks has something of an isolated character, 
although not situated within a furrowed scale.” 
“To give approximately the number of transverse rows of sense- 
hillocks is impossible, as I have not succeeded in recognizing them 
with the loup on the unwounded skin. Horizontal sections and 
microscopical investigations will be necessary to determine their 
number and arrangement.” ; 
“‘On the skin of the head, e. g., the region of the cheeks, beaker- 
shaped organs of the usual size are to be found, as well as others 
which are not inferior in size to the nerve-hillocks of the lateral 
lines, so that it is indifferent what name we give them.” 
‘“‘Tt is worthy of remark that the beaker-shaped organs of the pike 
and the organs of the lateral line on the trunk agree essentially in 
their structure.” 
Of Lota, Leydig says (p. 39): “In the head region the pores of the 
mucous canals are also present, but more numerous, and although for 
the most part restricted to the course of the mucous canals, they are 
also to be found in spots far from any mucous canal. The same is 
the case on the trunk. [If all of these points are actually pores of 
the system of mucous canals, the principal tubes of these must send 
off long branches in the corium to open in this manner. It is pro- 
bable, however, that the structures indicated are nothing but large 
beaker-shaped organs.” 
As has been remarked above, Leydig does not sufficiently dis- 
tinguish in the above passage and elsewhere between ‘beaker- 
shaped organs’ and ‘ nerve-hillocks.’ 
Amiurus possesses certain structures which I am inclined to believe 
are comparable to the scattered nerve-hillocks described by Leydig 
