OBSERVATIONS ON TERMITES IN JAMAICA 211 



These periodic changes from centripetal to centrifugal locomotion 

 are in part described for these same termites by Andrews and 

 Middleton, J. H. Univ. Circular No. 232, February, 191 1. 



Finally a like strip of paper but 3 mm. wide put across a 

 main trunk line down the tree checked the w^hole procession for 

 a whole minute before first one then another ventured across. 

 Almost all were workers. One from above went ^ inch to left 

 and then half across, i from below crossed on line of trail. Then 

 traffic resumed in 7 minutes, but still many banked up on the 

 upper side. 



Even when running over the paper rapidly every one under 

 the lens was seen to balk at the edge of the paper and to feel 

 it with the palpi. Many also hesitated a bit on the paper before 

 stepping off on the other side onto the trail. When the paper 

 was removed some hesitated while many rushed across, some 

 stood aside and examined the track but in 3 minutes most all 

 rushed along without check. When this paper was put loosely 

 across a continuous procession on the sand the termites passed 

 along under it without check, and when the paper was pressed 

 down in the sand there was but a slight check till all passed 

 back and forth as if paper were not there. 



Strips of grass across a track on tree acted like paper ; strips cut 

 2 mm. wide caused little delay but those of 4 mm. long delay. 



A smooth octagon pencil across track in sand caused the out- 

 going line to stop and act as if trying to get under it, or else 

 to go along pencil to right or left. Some turned back toward 

 the nest. On the other side of the pencil some turned to the 

 left along the side of the pencil. After many minutes some 

 from the nest got to the end of the pencil and made a wide 

 detour of a foot in the direction towards w^hich the old trail 

 led; but they did not find the old trail. One w^orker climbed 

 over the roughened metal end of the pencil, others followed 

 and soon a trail was established over this part of the pencil. 

 On removing the pencil a hesitating crossing from both sides 

 lead to reestablishment of the old trail. Likewise a piece of 

 smooth bamboo across the trail on the sand was not at first 

 surmounted but the termites after many minutes went around 

 it to make an accidental connection with another trail. Finally 

 some did climb over and then the trail was resumed straight 

 over the bamboo. 



