136 OF INSTINCT. Sect. XVI. 15. i. 



door, whenever they pafs or repafs. This hiftory was told me, 

 and the neft with its operculum (hewn me by the late Dr. Butt 

 of Bath, who was fome years phyfician in Jamaica. 



The production of thefe nets is indeed a part of the nature 

 or conformation of the animal, and their natural ufe is to fup- 

 ply the place of wings, when (lie wifhes to remove to another 

 fituation. But when me employs them to entangle her prey, 

 there are marks of evident defign, for (he adapts the form of 

 each net to its fituation, and itrengthens thofe lines, that require 

 it, by joining others to the middle of them, and attaching thofe 

 others to diftant objects, with the fame individual art, that is 

 ufed by mankind in fupporting the mails and extending the 

 fails of fhips. This work is executed with more mathematical 

 exactnefs and ingenuity by the field fpiders, than by thofe in 

 our houfes, as their constructions are more fubjected to the in- 

 juries of dews and tempefts. 



Beiides the ingenuity fhewn by thefe little creatures in taking 

 their prey, the circum fiance of their counterfeiting death, when 

 they are put into terror, is truly wonderful ; and as foon as the 

 object of terror is removed, they recover and run away. Some 

 beetles are alfo faid to pofTefs this piece of hypocrify. 



The carious webs, or cords, conftrufted b v fome young cat- 

 erpillars to defend themfelves from cold, or from infects of prey ; 

 and by fi Ik- worms and fome other caterpillars, when they trans- 

 migrate into aurelix or larvse, have defervedly excited the admi- 

 ration of the inquifitive. But our ignorance of their manner of 

 life, and even of the number of their fenfes, totally precludes 

 us from underflanding the means by which they acquire this 

 knowledge. 



The care of the falmon in choofing a proper fituation for her 

 fpawn, the Structure of the nefts of birds, their patient incuba- 

 tion, and the art of the cuckoo in depofiting her egg in her neigh- 

 bour's nurfery, are inftances of great fagacity in thofe creatures : 

 and yet they are much inferior to the arts exerted by many of 

 the infect tribes on fimilar occafions. The hairy excrefcences 

 on briars, the oak apples, the blafled leaves of trees, and the 

 lumps on the backs of cows are fituations that are rather produ- 

 ced than chofen by the mother infect for the convenience of her 

 offspring. The cells of bees, wafps, fpiders, and of the various 

 coralline infects, equally aflonifh us whether we attend to the 

 materials or to the architecture. 



But the conduct of the ant, and of fome fpecies of the ich- 

 neumon fly in the incubation of their eggs, is equal to any exer- 

 tion of human fcience. The ants many times in a day move 

 their eggs uearer the furface of their habitation, or deeper be- 



low 



