COXDYLURA CRTSTATA. 149 



to arrive at any positive knowledge of the way in which they are 

 made. All that one sees during their formation in dry soil is the 

 upheaval of a quantity of loose earth from a central point, which 

 point speedily becomes indistinguishable as the mound increases 

 in size, the only observable phenomenon consisting in a little heap 

 of dirt every particle of which seems to be in motion, as it steadily 

 approaches completion. The rapidity with which so much earth 

 is thrown up is one of the most perplexing things about it ; and 

 the peculiar motion of the mass leads to the notion that it is 

 traversed by galleries and that the Mole is at work within it and 

 not beneath the surrounding ground. On making a section of the 

 mound, however, it is found to contain no cavity unless it be a 

 mere tubular extension of the gallery, and this is absent in more 

 than half the hills examined. On opening the gallery beneath, no 

 chamber or tortuous excavation is discovered, and the fact at once 

 becomes apparent that so much earth as constitutes the hill could 

 not possibly have been obtained from the excavation in its imme- 

 diate vicinity, and must therefore have been brought from a dis- 

 tance. Just how it was conveyed to and forced through the orifice 

 leadin-^ into the hill I have until recently been at a loss to com- 

 prehend, but the opportunity to examine some freshly made mounds 

 in a wet pasture of rich loam or mould has cleared up the mystery. 

 These new mounds consisted wholly of compact cylindrical 

 masses of damp earth, having very much the appearance of Bologna 

 sausages, and measuring from three to five inches in length by one 

 and a half to two in diameter. It was noticeable that the size of 

 each was greater than that of the hole in the sod through which it 

 had been discharged, which circumstance shows that it must have 

 been subjected to considerable pressure during, expulsion. On 

 handling these masses they readily broke up, transversely, into a 

 number of more or less parallel discs, or lamellae, each of which 

 bore evidence of having been powerfully compressed. On exposure 

 to the air they soon lost their cylindrical form and crumbled, so that 



