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Insect Architecture. 



A caterpillar which builds a very similar cocoon to the 

 last-mentioned may be found upon a more common plant 

 the yellow snap-dragon or toad-flax (Antirrhinum linaria) 

 which is to be seen in almost every hedge. It is somewhat 

 shaped like a leech, is of a middle size, and the prevailing 

 colour pearl-grey, but striped with yellow and black. It 

 spins up about the beginning of September, forming the 

 outer coating of pieces of detached leaves of the plant, and 

 sometimes of whole leaves placed longitudinally, the whole 

 disposed with great symmetry and neatness. The moth 

 appears in the following June. 



Cypress-Spurge Caterpillar -(Acronycta Euphrasies} with a Cocoon, on a brancb. 



It is worthy of remark, as one of the most striking 

 instances of instinctive foresight, that the caterpillars which 

 build structures of this substantial description are destined 

 to lie much longer in their chrysalis trance than those which 

 spin merely a flimsy web of silk. For the most part, indeed, 

 the latter undergo their final transformation in a few weeks ; 

 while the former continue entranced the larger portion of a 

 year, appearing in the perfect state the summer after their 

 architectural labours have been completed. (J. R.) This 

 is a remarkable example of the instinct which leads these 

 little creatures to act as if under the dictates of prudence, 

 and with a perfect knowledge of the time, be it long or 

 short, which will elapse before the last change of the pupa 

 takes place. That the caterpillar, while weaving its cocoon 



