The Tachytes 



of the bag and cements them with the fluid 

 from its spinnerets, which hardens at once. 

 When this task is finished, the house has 

 still to be closed, for it has been wide open 

 all this time to permit of the renewal of the 

 store of sand as the heap inside becomes 

 exhausted. For this purpose a cap of silk 

 Is woven across the opening and finally en- 

 crusted with the materials which the larva 

 has retained at its disposal. 



The Tachytes builds in quite another fash- 

 Ion, although its work, once finished, does 

 not differ from that of the Bembex. The 

 larva surrounds itself, to begin with, about 

 the middle of its body with a silken girdle 

 which a number of threads, very irregularly 

 distributed, hold in place and connect with 

 the walls of the cell. Sand is collected, 

 within reach of the worker, on this general 

 scaffolding. Then begins the work of minor 

 masonry, with grains of sand for rubble and 

 the secretion of the spinnerets for cement. 

 The first course is laid upon the fore-edge of 

 the suspensory ring. When the circle Is 

 completed, a second course of grains of sand, 

 stuck together by the fluid silk, is raised upon 

 the hardened edge of what has just been 

 done. Thus the work proceeds, by ring- 

 shaped courses, laid edge to edge, until the 

 i6i 



