INTRODUCTION. 89 



kinds generally formed by these family associations. 

 When they first issue from the egg, they arrange 

 themselves side by side in regular lines, two or three 

 deep, and eat their way along the surface of the 

 leaf, advancing simultaneously and with as much 

 regularity as if they were executing a military 

 manoeuvre. In this systematic way they speedily 

 consume the leaf for rather more than half its thick- 

 ness ; leaving, however, untouched the inferior epi- 

 dermis and the nervures, as these are to form the 

 canvass and cordage, if it may be so expressed, of a 

 portion of their future tent. At an early period 

 some of them may be seen carrying their lines of 

 silk from one side of the leaf to the other, and as 

 these increase in number^ the latter, now become 

 thin and pliable, gradually acquires a concave shape. 

 By the aid of additional spinners, the threads are 

 multiplied till they form a continuous web or veil, 

 the silk of which is remarkable for its whiteness. 

 Under this, as a kind of roof, they find shelter from 

 the weather, and make little excursions when in 

 want of additional food. 



Now busily convened, upon the bud 

 That crowns their genial branch, they feast sublime ; 

 And spread their muslin canopy around, 

 Pavilioned richer than the proudest kings. 



Several leaves, prepared in this manner, are gene- 

 rally necessary to afford accommodation to an entire 

 colony. These slight erections, however, are de- 

 signed merely for temporary protection, and are all 

 abandoned for one of a more durable construction. 



