Chap. II. EARTH SWALLOWED AS FOOD. 



107 



rise like towers (see Fig. 2), with their sum- 

 mits often a Httle broader than their bases, 



Fig. 2 



Tower-like casting from near Nice, constructed of earth, voided 

 probably by a species of Perichaeta : of natural size, copied from 

 a photograph. 



sometimes to a height of above 3 and often 

 to a height of 2^ incbes. The tallest of those 



greatly surprised to see how closely they resembled castings sent 

 to me from near Calcutta, where it is known that species of 

 Perichieta abound. 

 6 



