6 
limb on the one side and the posterior limb on the other are moved 
forward at the same time. If disturbed, the gills are at once con- 
tracted, the anterior and posterior limbs are folded closely to the 
body and the larva propels itself wholly by means of its tail. The 
decapitated larvae of this stage show no noteworthy differences from 
the normal. 
Larvae 35-36 mm. Some observations were made on the method 
of taking food. This has been well described by Wuitman for the 
normal larva as follows: “The dish containing the young was kept 
on the table, where without being moved, food could be offered in 
perfect quiet. I used the tiniest bits of raw beef and offered only 
one piece at a time, which I held in small forceps or on the point 
of a needle a little in front of the animal to be tested. If the meat 
is held closely enough to touch the head, the animal is frightened and 
may retreat with such haste as to alarm all its companions. If the 
bait is held a little to one side, an inch or so away, and very quietly 
for a minute or more, a slight turning of the head in that direction 
may be noticed,—in case the animal is ready to eat and feels con- 
fidence enough to try to reach it. The turning of the head is done 
very cautiously and almost as slowly as the minute-hand of a clock 
moves, so that one may become aware of it, not by seeing the move- 
ments, but by noticing the inclination of the head to the axis of the 
body. If there be a decided turn of the head of this kind, the case 
is hopeful, as it shows an interest which may be encouraged to action 
by bringing the bait a little nearer, but very slowly and without jerky 
movement. Halting about half an inch away, wait for further move- 
ments on the part of the animal; if you are fortunate enough not to 
have frightened it away. If the animal’s courage holds out—in most 
cases it does not in the first trials—it will soon begin to move, but 
with a slowness that tires the observer’s patience. The head at length 
comes to a point a quarter of an inch away, more or less, and after 
making sure of the position of the bait, which seems to be done less 
by the aid of the eyes than by the sense of touch, the animal tries 
to seize it by a quick side movement of the head and a snap of 
the jaws.” 
An attempt was made to determine, if the decapitated larvae 
would respond to gently moving objects in close proximity. A bit 
ot cork about 2 mm. square was held on the point of a needle and 
moved gently to and fro in close proximity to the anterior end of 
