1926] Color and Sex in the Indian Walking Stick 153 
After the insects had attained sexual maturity, two other 
green individuals were transferred to red cages and two dark 
brown individuals to green cages. No color change was observed. 
Apparently the color present after the last moult is permanent. 
The question as to the reasons for the original variations in 
color of individuals occupying the same environment as found 
in our cultures remains unanswered. The only explanation 
which suggests itself is the following: The insects feed during the 
early part of the night attaching themselves before dawn to a 
branch or any other suitable support, and remaining motionless 
in the same spot throughout the day. They show a marked 
tendency, in captivity at any rate, to return to the same support 
day after day. If the slight differences which exist in the il- 
lumination and background are sufficient to bring about the 
differences in color, this habit may be responsible for the ob- 
served variation. 
Fryer (1913), working with a bisexual walking-stick, Cli- 
tumnus cuniculus, from Ceylon, in which both yellow and green 
forms are found, interpreted the color differences as being in- 
herited. The color, according to his hypothesis, is due to action 
of a single factor pair, yellow being dominant over green His 
data, however, do not furnish the necessary proof for his hypo- 
thesis. The males are uniformly of the same color, and he was 
thus able to assign to the male used in a given mating the par- 
ticular genetic constitution necessary to explain the proportions 
obtained in the progeny; but apparently the tests necessary to 
determine the correctness of his assumptions were not made. 
The fact, as shown by Pantel and de Sinety (1918), that* 
coloration in several other species of walking-sticks in addition 
to Dixippus, is dependent upon the environment, suggests the 
desirability of reexamining the behavior in Clitumnus from this 
viewpoint. 
Among a total of several thousand individuals reared in our 
cultures, two males and one gymandromorph appeared. The 
sporadic occurence of males and gymandromorphs has also been 
reported by others. Nachtsheim (1922) has suggested that 
non-disjunction is responsible for their appearance. In the Or- 
thoptera generally, the female is characterized by the presence of 
