SECT. XVI. 15. i. OF INSTINCT. 1 35 



their own length out of the water, expecting to get into the 

 trough above. 



This evinces that the ftorge, or attention of the dam to pro- 

 vide for the offspring, is ftrongly exerted amongft the nations 

 of fifti, where it would feem to be the moft negle&ed ; as thefe 

 falmon cannot be fuppofed to attempt fo difficult and dangerous 

 a talk without being confcious of the purpofe or end of their en- 

 deavours. 



It is further remarkable, that moft of the old falmon return 

 to the fea before it is proper for the young fhoals to attend them, 

 yet that a few old ones continue in the rivers fo late, that they 

 become perfectly emaciated by the inconvenience of their fitu- 

 ation, and this apparently to guide or to protect the unexperi- 

 enced brood. 



Of the fmaller water animals we have ftill lefs knowledge, 

 who neverthelefs probably pofTefs many fuperior arts ; fome of 

 thefe are mentioned in Botanic Garden, P. I Add. Note XXVII. 

 and XXVIII. The nymphx of the water-moths of our rivers, 

 which cover themfelves with cafes of ftraw, gravel, and {hell, 

 contrive to make their habitations nearly in equilibrium with 

 the water ; when too heavy, they add a bit of wood or ftraw ; 

 when too light, a bit of gravel. Edinb Tranf. 



All thefe circumftances bear a near refemblance to the delib- 

 erate actions of human reafon. 



XV. We have a very imperfect acquaintance with the vari- 

 ous tribes of infects : their occupations, manner of life, and even 

 the number of their fenfes, differ from our own, and from each 

 other ; but there is reafon to imagine, that thofe which pofiefs 

 the fenfe of touch in the moft exquifite degree, and whofe oc- 

 cupations require the moft conftant exertion of their powers, 

 are endued with a greater proportion- of knowledge and inge- 

 nuity. 



The fpiders of this country manufaflure nets of various 

 forms, adapted to various (ituations, to arreft the flies that are 

 their food ; and fome of them have a houfe or lodging-place in 

 the middle of the net, well contrived for warmth, fecurity, or 

 concealment. There is a large fpider in South- America, who 

 conftrudls nets of fo ftrong a texture as to entangle fmall birds, 

 particularly the humming bird. And in Jamaica there is an- 

 other fpider, who digs a hole in the earth obliquely downwards, 

 about three inches in length, and one inch in diameter ; this 

 cavity (he lines with a tough thick web, which when taken out 

 refembles a leathern purfe ; but what is moft curious, this houfe 

 has a door with hinges, like the operculum of fome fea (hells ; 

 and herfelf and family, who tenant this neft, open and fhut the 



door, 



