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the larva. The first response of the larva in all cases was to recede 
from the moving objects: slowly, if the cork were moved gently, 
rapidly, if the cork were moved quickly. By exercising patience and 
care it was possible to cause the larvae in most cases to turn the 
anterior portion of the body toward the cork and in a number of 
eases to follow the cork short distances. Some of my decapitated 
larvae responded to the vibrations made by passing a needle to and 
fro in the water. They would slowly turn toward the source of dis- 
turbance and then move toward it. These observations confirm the 
supposition by Professor Wuirman that in orientation Necturus relies 
but little on the sense of sight. 
Pigmentation. 
Larvae 11-12 mm. The first appearance of pigmentation is found 
in larvae of this length. When observed under the binocular micro- 
scope this pigment appears as minute black dots lying deep in the 
semi-transparent connective tissue. If these structures be continuously 
watched for a few hours under the binocular microscope, or even 
examined at short intervals, it is easily seen that they gradually in- 
crease in size and slowly approach the surface. 
Larvae 15-16 mm. In the preceding stage but a few of the 
chromatophores were at the surface of the dermis, but in the present 
stage large numbers of them have reached the surface and through 
their widely branching processes form an open meshwork. While 
these superficial chromatophores are most numerous over the dorso- 
lateral surface of the head, they also are scattered along the body, 
being confined for the most part to a pair of irregular dorso-lateral 
bands which extend from the region of the gills to the posterior 
limb buds. 
As previously stated, one of the most notable changes during 
the 24 hours following decapitation takes place in the black chromato- 
phores. The protoplasmic processes in nearly all of them are greatly 
contracted and in some so completely that there remains but a small 
black sphere in place of the widely branching chromatophores of the 
normal. A comparison of Figs. 2 and 3 will emphasize this fact. 
Larvae 17-18 mm. The chromatophores show a marked increase 
in number over the preceding stage. In a number of larvae, they 
have extended well down over the upper surface of the yolk. In 
the head region there is a median dorsal line which is almost free 
