NESTING ARCHITECTURE 



unbroken edge of the pit the task of filling up had begun. 

 From the lower points (A) there extended a series of 

 elevations (a, b, c, d), which marked the upper outline 

 of an arc. Beyond this, toward the base of the hill, 

 and parallel with it, was a like series (d, e, /), bending 

 around the depression next to and parallel with its 



Fig. 28 PRELIMINARY ENGINEERING 



Mound-making ants filling up a break made in a mound 



by a cow's foot 



lower rim. These little pillars were not alike in shape, 

 and it was quite noticeable that their height gradually 

 increased from the unbroken margin of the mound 

 toward the centre, where it was highest. Yet, through- 

 out, their tops conformed to the general surface of the 

 cone, the diminishing depth from centre to edge being 

 met by a corresponding lowering of the columns. From 

 these, and from similar elevations around the rim of the 

 track, as centres of operation, the work of covering-in 

 proceeded with great advantage (Fig. 28). A number 

 of straws were worked into the columns apparently as 

 braces ; and in one of the little hollows were piled many 

 shells of cocoons from which antlings had just been 



4 30 



