56 CHARLES \\ . HARGITT 



American species the subject of special study in this particular 

 phase of behavior. 



I shall begin my account with observations made upon 

 H. versicolor, and later take up similar studies of H. arborea, 

 with a comparison of the behavior of the two species as relates 

 to color changes. 



The present series of studies had their origin in some casual 

 observations made upon H. versicolor in the early autumn of 

 1906, both as to color variations exhibited by specimens under 

 essentially identical conditions of light, temperature, etc.., and 

 as to a peculiar habitat that seemed unique. Noting first the 

 matter of habitat it may suffice to merely state the fact that 

 the specimens were found perched upon the black iron fence 

 of a cemetery along which was a cement walk leading to an open 

 field often sought as a collecting ground for various specimens 

 liable to afford laboratory material. The special position of 

 the specimens was upon the flat surface of projecting supports 

 for barbed wires strung above the fence proper. These supports 

 like the other parts of the fence were painted dead black. Evi- 

 dently they had climbed up the posts from the ground and 

 had found a congenial resting position ; but just what may have 

 induced them to choose such a place it is impossible to suggest. 

 But the fact of habitat aside for the time, my next point of 

 curiosity was found in that the first specimen was very light 

 grey in color, appearing almost white in contrast with the 

 black support on which it was reposing. I merely paused 

 to observe the little creature in its novel position, but came close 

 to it to make the inspection exact, but without disturbing it in 

 the least, as it seemed utterly unconcerned and unafraid, blink- 

 ing sleepily, but without other sign of activity. 



Somewhat further along the same course a second specimen 

 was observed in exactly the same general position, perched 

 at ease on the shelf, backed up against the post. In this case 

 the color was very dark, and so in striking contrast to that of 

 the first. As before, I paused for a few minutes and scrutinized 

 the specimen as carefully as I could without actually picking 

 it up, which might easily have been done, for it made not the 

 slightest attempt to evade capture. However, it was passed 

 with nothing beyond the cursory examination mentioned. 

 A few days later I was passing along the same course with a 



