STATES OF INSECTS. (Larva.) 217 
shaped like a reversed boat?. The animal begins by 
laying the foundations of one of the ends of her cocoon, 
she adds new threads to this small beginning, and so 
proceeds, As the work advances she retreats back- 
wards, and her body is situated nearly in the same line 
with the cocoon she has begun, and quite out of it; she 
only touches with her head and legs its anterior margin. 
When half the cocoon, or rather of its exterior layer, is 
finished, she suspends her operations for some moments. 
She then for the first time introduces her head znto 
this demi-cocoon, and turns herself in it by doubling 
her supple body, and passing one part over the other, 
so that at last she manages to bring her tail into the 
pointed end of the cocoon, the head and the anterior 
half of her body remaining without. Thus situated, she 
commences her operations afresh. At a distance from 
the margin of the demi-cocoon, equal to its length, she 
begins to spin the pointed end of the other moiety, the 
length of her body serving her as a measure that en- 
ables her to begin at the proper distance from it. This 
new portion she spins in the same manner as the other ; 
but as she is prevented by the demi-cocoon in which the 
posterior part of her body is lodged from retreating 
backwards, she contracts her body more, which answers 
the same purpose. When the new work is so advanced 
that she can no longer contract her body, she bends the 
anterior part of it considerably, and reverses her head. 
When the distance between the margin of the two 
halves of the cocoon is very small, so as no longer to 
admit the head between them, in order to unite them 
she is obliged to have recourse to another manceuvre. 
° De Geer i. f, xxxii. f. 3—6. 
