OAK-BARK BUILDERS. 99 



different stages of progression, and employed on each of them 

 we can discern a single artizan, who is preparing the abode 

 for his own solitary occupation. This labourer is a small yel- 

 lowish white caterpillar,, tinged with red, each segment of his 

 body being studded with tufts of red hair. He has fourteen 

 feet, and the upper part of his body is more flat than in the 

 generality of the caterpillar crew. He has also two brown 

 spots behind the head. On commencing operations he mea- 

 sures (using his body as a rule) the place intended for his 

 structure the basement of which is of a triangular form, 

 with the apex at the lower end. "The bricks or tiles of 

 which the building is composed are small rectangular strap- 

 shaped pieces of the outer bark, cut out from the immediate 

 vicinity. Upon the two longest sides of the triangular base 

 he proceeds to build uniform walls, also of triangular shape, 

 and both gradually diverging from each other as they increase 

 in height. When finished, the little architect proceeds to 

 draw them together by pulling them with silken cords till they 

 bend and converge and meet. When the two longest sides 

 are thus joined, an opening is still left at the upper and 

 broadest end of the triangle, which being filled up in a similar 

 manner, the building is complete"*- -without, and, when 

 tapestried with silk, is furnished within. This clever bark- 

 builder, for whose operations May is the usual season, is the 

 caterpillar of a moth.f 



* Insect Architecture, p. 198. t Pymlis Stncjidalis. Kirby. 



