AMERICAN HYJIENOrTERA. 



2G3 



tions is very plain ; from the little raised columns and mounds figured 

 above, the work of covering in could proceed with the greatest ad- 

 vantage. The elevations 6, c, f?, were evidently guaged by the height 

 of the edge of the hill at A, thus marking the depth of the track on 

 that line. The diminishing depth was met by a corresponding lower- 

 ing of the lunettes i, i, t, and at other points in the excavation the 

 same facts held good. 



The above operations began on Saturday morning; on 3Ionday 

 morning the cavity was two-thirds filled. Very strangely the work 

 did not connect with the face of the break towards the summit of 







Fig. 3. — Engineering work; filling up a break. 



the hill, but a deep trench or gallery had been preserved all the way 

 across, the wall being maintained intact. The photograph was taken 

 on this day, and the track with this trench may be seen in the plate. 

 Nor was there any appearance here of the formation of the galleries 

 above described; it was dead filling in. In one of the little hollows 

 the shells of cocoons, out of which aiitlings had just been delivered, 

 were piled up, apparently to assist in the filling. I had before ob- 

 served these being carried from this hill and deposited on the stones 

 outside. A number of straws were worked into the columns, evi- 

 dently as braces. A few feet from this large mound was a small hill, 

 one of its off shoots, which even before the rain had shown much 

 activity in construction, for the surface was covered with fresh pellets. 

 The shower had inspired the inmates of this young community with 

 amazinn; zeal. 



