208 E. A. ANDREWS 



lating centripetal termites near the far side of the glass and 

 then returned to the near side by a route some distance to the 

 side of the glass . Then many termites ran the same side track 

 and the procession was permanently established around the glass. 

 Even when the glass w^as removed the procession continued to 

 make the detour which for some days was a visible bend in an 

 otherwise straight track. 



At first the guards had stood in a row on opposite sides of 

 the glass but when the procession moved in the detour the 

 guards stood along each side of the procession and no attention 

 was paid to the glass. 



Thinking the termites might use some pine wood sawdust in 

 making walls along a horizontal path on boards, some was 

 dropped across the path. The workers at once stopped running 

 and only soldiers were to be seen. These drew back and very 

 cautiously felt toward the sawdust with the antennae ; often one 

 then turned tail and ran away. When a short train of workers 

 came running up the trail they stopped as if shocked before 

 touching the sawdust though they did not touch the soldiers 

 nor were there any vibrating movements that might have given 

 warning sounds. The workers seemed not aw^are of the danger 

 till they almost touched it. Some soldiers from the first advanced 

 around the sides of the sawdust and investigated with out- 

 stretched antennae and raised heads. Gradualh' some went 

 nearly past the pile of sawdust. One worker finally picked up 

 a fragment and carried it away, but the pile remained for days 

 without further use while in a few hours the procession had 

 reformed in a detour about the sawdust. 



When termites were running rapidly on branching trails on 

 the loose sand in spreading out from a tree containing a trans- 

 planted community the sand was disturbed by a stick draw^n 

 across the trail. The termites checked at the edges of the minia- 

 ture gully as if against a solid object till, after several had accumu- 

 lated from the sparse procession, a few ventured on in the same 

 general direction as the trail and came to the old part of the 

 trail, when the procession w^as resumed across the new sand. 

 When the trail was depressed by the finger a similar gully 

 resulted but the termites ran across this with much less delay 

 as the material of the old trail had not been removed. 



At a point, B, where a trail forked, 2 inches of the sand along 



