Il8 REIPORTS OF INVESTIGATIONS AND PROJECTS. 



Individuals of 20 species of coral-reef fishes were fed, living, to the same 

 colony of snappers. They were conspicuous in color and pattern, many of 

 them typically "warningly" colored. All were readily taken. 



While the gray snapper is thus shown to possess the qualities necessary 

 to the establishment of a warning reaction (assumptions 2, 3, and 4), and 

 while such a reaction may be artificially established (assumption 3) and is 

 long retained (assumption 4), yet feeding experiments furnish no evidence 

 of the avoidance of any color in itself (assumption i) or of the existence in 

 coral-reef fishes of that combination of conspicuous coloration and disagree- 

 able qualities necessary to the theory of warning color. 



Dr. Charles R. Stockard carried out an interesting series of studies of 

 the habits of a walking-stick insect, which is common upon the bay cedars 

 of the Tortugas, and he also conducted elaborate observation of certain 

 phenomena of regeneration in Cassiopea. Detailed studies of the normal 

 relations of supposedly "protectively colored" insects have not hitherto been 

 made. The habits of the insect studied by Dr. Stockard are such as would 

 reinforce the efficiency of its remarkably "protective" coloration. Dr. Stock- 

 ard's preliminary report of his studies is as follows : 



Summary of Investigations Conducted at the Carnegie Laboratory for 

 Marine Biology, Tortugas, Florida, Season of 1907, by Charles R. Stock- 

 ard, Cornell University Medical College, New York City. 



(i) A study was made of the behavior of Aplopus mayeri, a "walking- 

 stick" found to be rather common on the island. Its wild habits, such as 

 movements, feeding, mating, etc., were observed, and the insects were seen 

 to be nocturnal, becoming active and moving about on the food-plant shortly 

 before sunset. This activity was kept up until the faint daylight of morning, 

 when they came to rest on any part of the limb that they happened to be 

 at this time. They assume a protective attitude during the day and are ex- 

 tremely difficult to locate. The females vary considerably in color, as do the 

 stems of the food-plant, Snriana maritima, though they seem to fail com- 

 pletely to take advantage of this variation, the light-gray type of female 

 often resting on the darker branches, and vice versa. When disturbed, they 

 usually drop bodily from their position and catch on a branch below, or, at 

 times, fall entirely to the ground, where they may feign death and sometimes 

 lie motionless on their backs for several minutes. Most of the habits of this 

 protectively constructed animal are much the same as one would imagine 

 to be most advantageous to their possessor under the given conditions. 



The mating habits were closely studied. They were found to pair most 

 frequently at night, though several pairs were observed in copulo during the 

 mid-day. 



A number of experiments were conducted to test the modification of their 

 behavior. The eyes were blackened; antennae removed; they were subjected 

 to various noises and colored lights, and studied in the dark-room during 

 the day. The details of these experiments will be published in the contribu- 

 tions from the Laboratory. 



Experiments were also conducted to test the mating instincts of Aplopus. 

 I finally succeeded in inducing two males, at different times, to copulate 



