196 E. A. ANDREWS 



When the warping of an arcade throws it away from a branch 

 a new floor may be constructed along the arch and then the 

 termites run from the usual arcade out into a tubular bridge 

 for some inches and then back to the arcade with its bark floor. 



The floor of the arcade seems clean but when termites are 

 confined in glass they smear it over with anal material before 

 they can walk up it and escape. The suggestion of purpose and 

 means in this case offers an interesting problem for future 

 study. 



The rate of arcade building was found to depend upon the 

 readiness with which the termites could obtain not only vegetable 

 tissue but also water. ■ Without enough of these elements they 

 would run for many days uncovered; and when only water was 

 abundant there was more smearing of dark material over the 

 path. Before any other sign there is observable a line of minute 

 dark excreted drops along the sides of the trail to be followed 

 by definite wall building. Hence we may suppose the building 

 of the arcades is made up of the two factors, the need of dis- 

 charging the effects of digestion, along the road, and the tendency 

 to carry aw^ay some of the food material: the use of one end of 

 the body being correlated with the use of the other. 



When the arcades were punctured with a needle the method 

 of repair was exclusively the application of the anal cement. 

 In the minute hole there appeared first one or two antennae 

 which seemed to measure the hole, then the anal end was pre- 

 sented and a drop secreted which tended to stretch across the 

 hole but the surface tension film soon broke and the drop with- 

 drew to one side and dried out as a crescent along the edge of 

 the hole; then a second palpation with antennae, a second drop 

 and so on until a fifth drop, or so, finally remained stretched 

 across the the most minute remnant of the hole. It was notable 

 that the successive drops were so placed as to close in the hole 

 from all sides, after the manner of the portions of an iris dia- 

 phragm. Probably such cementing work finishes the smooth 

 inside of the arcade which is comparable to a rough concrete 

 wall faced inside with pure cement. 



The second great area of activity of the termites is the region 

 of food and water getting. The termites probably get water 

 from dead moist wood and from dew and rain ; in captivity they 

 drink greedily from moist wood, filter paper, or stones and 



