IMft 



those of fishes, partly placed on each ether. The case 

 Las sometimes for its last covering a kind of mantle, 

 which almost entire!}' incloses it, and is composed of 

 two principal pieces, whose figure resembles that of a 

 llvalve shell. Moths that procure the matter for their 

 clothing from their own fund, must be able to lengthen 

 and widen it at pleasure ; the expense attending the ob- 

 taining of it was too great to admit of their making a 

 new one as often as there should be occasion : so that 

 they are able to enlarge it in a wonderful manner. 

 They do not add. breadths to it as the domestic moths 

 do ; but slit it from one part of it to another, according 

 to its length, and immediately fill up the intervals with 

 new threads, of a length proportioned to the space re- 

 quired. This case serves them likewise as a kind of 

 cone, wherein they transform themselves into butter- 

 ;flies. 



You have taken a survey of the produce of a multi- 

 tude of different insects, and are with good reason 

 astonished at the prodigious variety contained in them, 

 all relative to one and the same general end, and all of 

 them likewise as much diversified as those of our arti- 

 zans. How does it happen, that a mpngst so many in- 

 sects as prepare themselves for their metamorphosis, 

 some hang by their hind part, others fasten themselves 

 \vith a girdle, whilst others make themselves cones I 

 Bow came it to pass, that of those that construct these 

 cones* some form them of pure silk, and others com- 

 pose them of matter of different kinds ? Why is the 

 form of these cones so various in different species? 

 Wherefore do some insects so artfully roll up the leaves 

 of plants, and others only fasten or fold them together? 

 How can we account for the mining of these leaves by 

 some only, and that the rest should not all mine them 

 In the same manner ? In short, how shall we assign a 

 reason why the nioths are not all clothed in the same 

 dress? 



,11 these wherefores, and a thousand others that may 



