11 
Closing of wounds. 
The manner and rate of the closing of wounds in the normal 
larvae has been made the subject of an earlier paper (Am. Journal 
of Anat. 1907). The observations made at that time serve as a basis 
for the following comparison. 
Five larvae, which had been decapitated some. two weeks previous 
were selected for the experiments. Each larva was placed on a bed 
of cotton in a solid watch glass. The larva was thus held in position 
while a small piece of skin, about 2 mm. long and 1 mm. wide was 
excised in the mid-dorsal region. As soon as the excision was made, 
the larvae were placed in separate dishes and examined at short inter- 
vals under a binocular microscope. By this method it was possible to 
follow the rate of closure. Although the decapitated larvae were less 
densely pigmented that the normal, it was possible to observe the 
movement of the epidermis over the dermis. As stated in the earlier 
paper the single large gland cells of the epidermis are observed to 
move over the pigmented dermis. 
The time required for the cut margins of the epidermis to ap- 
proximate and thereby close the wound was on the average a little 
slower than in the normal. The average time of closure in the normal 
was found to be above one and a half hours. In the decapitated the 
time averages about two hours. The movements of the dermis as 
indicated by the position of the dermal chromatophores is likewise 
somewhat slower in the decapitated than in the normal. In the normal 
the time is approximately twelve days while in the decapitated it is 
about two weeks. 
The closing of wounds in the decapitated larvae proceeds in the 
same manner as in the normal, but at a somewhat slower rate. 
Reaction to light. 
Some observations in reaction to light of the normal and decapi- 
tated larvae were made the subject of an earlier publication (Journ. 
Comp. Neurol. and Psychol. 1908). More recently the experiments 
and observations were repeated as follows. 
One half of a small glass aquarium was painted black and this 
portion was then covered by a black board. Twenty larvae which 
had been decapitated two weeks earlier were placed in the aquarium. 
Two hours later they were all in the darker portion. Sixteen orient- 
ated themselves in such a way that their tails were toward the lighter 
