48 Papers from the Marine Biological Laboratory at Tortugas. 



The males do not so constantly assume the position with the first legs 

 extended. This attitude is less essential for them than for the females, since 

 they are found as a rule among the leafed branches, where their greenish legs 

 are inconspicuous. Their slenderer proportions and smaller size also make 

 them more difficult to see. At times, however, the males do straighten their 

 first pair of legs forward and assume the position so common to the female. 



The more common occurrence of the greenish males among the foliage 

 and of the brown females upon the brown stems of the plant suggest the 

 case of Mantis rcligiosa. Di Cesnola^ records this mantis as occurring in a 

 green and a brown form in Italy, the green form being always found upon 

 green grass and the brown form upon grass burnt by the sun. He found 

 that when 25 individuals of the green form were tied on brown grass all 

 were killed in 11 days, while 20 tied on green grass were all alive after 17 

 days. The results were similar when the brown form was tied on green and 

 burnt grass. 



MOVEMENTS OF APLOPUS. 



Aplopns is nocturnal in its habits. During the day it sits motionless 

 among the branches, but as the sun's rays weaken the males begin to move 

 about first, and later the females. Their manner of walking is peculiarly 

 interesting. They resemble sticks crawling about on legs. The legs are 

 moved in a stiff manner and the insect progresses slowly as a rule, although 

 they sometimes move at a rapid gait. While walking among the branches 

 or on a flat surface they often show a lateral swinging movement, the foot- 

 hold forming a fixed point, while by bending the tarsal and knee joints the 

 body is swung sidewise, sometimes with an amplitude of more than half an 

 inch. This movement suggests to the observer the swinging or waving mo- 

 tion of branches and stems when shaken, or blown by the wind. The male 

 has also a peculiar quivering movement that is sometimes performed at 

 intervals while moving about the branches. This motion is more to be 

 associated with the mating instincts, as is shown below. In the evening 

 Aplopus shows a tendency to climb upward, being negatively geotropic. It 

 will then often turn and go upward if the twig is inverted after it has 

 reached the top. 



The males travel greater distances during the night than do the females. 

 Three females under observation did not move more than 2 feet from 

 their original positions within a period of two days, yet others were found 

 to migrate to parts of the bushes 10 or 12 feet distant during a single night. 

 The males usually travel many yards in a night and it is almost impossible 

 to keep track of them for more than one day. 



Aplopus avoids or escapes its enemies in the following ways : On several 



'Di Cesnola, A. P. Preliminary note on the protective value of color in Mantis 

 rrligiosa. Biometrika, III, p. 58, 1904. 



