N D E X. 



'S43 



bon«, and almoft every part of the body, as well as by the lungs, in. Rerpiratioa 



offifhes, il6. Refpiration of infefts, ii8. 

 Retina. External objedts painted on it in an inverted pofition, i8o. Why obj efts are 



feen ereft notwithftanding the inverfion of the piftures, 18 1, 182. Why vifion is 



fingle though a pifture is painted on each eye, 183, 184. 

 Roebuck. His artifices and manners, 402. 



S 



Saliva, a powerful folvent, 165. 



Salmons. Of their migrations, &c. 49J. 



Scale. Of the progreflive fcale of beings, 520, &c. 



Scallop. Its motions defcribed, 139. 



Scarabaei, or the jjeetle tribe of infefts, an account of them, 89. 



Scorpion. Account of it, 98. 



Sea-nettle capable of being ingrafted, 40. 



Seal. Sketch of his manners, 67. 



Seafons. See love. 



Seeds. Analogies between them and the eggs of animals, 35. 



Seeing. See fenfes. 



Senfation implies the perception of pleafure and pain. May be fufpended without 

 death, 19. See fenfes. Theory of fenfation, 1 74. 



Senfes. Filhes endowed with the fenfe of hearing, 80. Of the fenfes in general, i<5o^ 

 Of the fenfe of fmelling, 161. Men, as well as brutes, aflifted in the feleftion of 

 food by the fenfe of fmelling, 162. Moft odours produflive either of pleafure or 

 pain, 163. The fenfe of fmelling in fome animals remarkably acute, 164. Of tailing, 

 165. The organs of tafte and fmeliing affift each other, ibid. Senfe of tafting com- 

 paratively grofs, 166. Senfe of hearing, 167. The pleafures derived from it, 171. 

 Senfe of touch, 174. Senfe of feeing, 177 ; conveys no idea of dlftance, 184. Er- 

 rors of vifion correfted by touch, 155. Of the fenfe of fmelling alone, 187; of- 

 hearing alone, 1S95 of fmelling and hearing united, ibid. ; of tafte alone, and united 

 with fmelling and hearing, 190 ; of fight alone, ibid. ; of fight united with fmell, 

 hearing, and tafte, 19'; of touching alone, ibid.; of touch united with fmelling, 

 194 ; of hearing, tafte, and touch united, ibid. Of fight united with all the other, 

 fenfes, ibid. 



Sepia. See cuttle- filh. 



Serpents caft their ikins annually, 290. 



Sexes. Of the lexes of animals, 236 Their intercourfe not always neceflary for mul- 

 tiplication, 239. See multiplication. Caterpillars are of no fex, 739. Among the- 

 larger animals, the difference of fize between males and females is not confiderablej. 



2.3g.i3i 



