OF SOCIABLE CATERPILLARS. 101 



experiment of placing the leader at the rear, in order 

 to observe how he would bear the degradation, and to 

 ascertain if the head of the column would have been 

 thereby changed."* 



Besides those larvae which conceal themselves, and 

 transform in their cocoons, there is a tribe which 

 burrow under ground ; these have been called Earth 

 Mason Caterpillars. Among them may be ranked 

 the Death's Head Sphinx, plate LXXI. Some of these 

 make a rude masonry of particles of earth, united by 

 silk or gluten, varying in form according to the 

 species. 



NEST OF THE EARTH MASON LARVA, 

 ( The Water JBetorty Mcth,) 



which is generally of an oblong shape, although they 

 are not always uniform. The interior is smooth and 

 polished, lined with a fine tapestry of silk. 



* BREWSTEK'S Journal of Science, ii. 94. 



