Siicr.XXXlX. 6. GENERATION. 587 



thy and quality, by the pleafurable or painful fen- 

 fations, which produce or accompany thofe fecre- 

 tions. And that the pleafurable fenfations arifing 

 from thefe fecretions may conftitute the unnamed 

 pleafure of exiftence, which is contrary to what is 

 meant by taedium vitse, or ennui ; and by which we 

 fometimes feel ourfelves happy, without being able 

 to afcribe it to any mental caufe, as after an agree- 

 able meal, or in the beginning o of intoxication. 



Now it would appear, that no fecretion or excre- 

 tion of fluid is attended with Ib much agreeable 

 fenfation, as that of the femen ; and it would thence 

 follow, that the glands, which perform this fecre- 

 tion, are more likely to be much affected by their 

 catenations with pleafurable fenfations. This cir- 

 cumftance is certain, that much more of this fluid 

 is produced in a given time, when the objedl of its 

 excluiion is agreeable to the mind. 



2. A forcible argument, which fhews the necef- 

 fity of pleafurable fenfation to copulation, is, that 

 the at cannot be performed without it ; it is eafily 

 interrupted by the pain of fear or bafhfulnefs ; and 

 no efforts of volition or of irritation can eflec-l this 

 procefs, except fuch as induce pleafurable ideas of 

 fenfations. See Sea. XXXIII. I. i. 



A curious analogical circtimflance attending her- 

 maphrodite infers, as fnails and worms, ftill fur- 

 ther illuftrates this thueory; if the fnail or worm 

 could have impregnated itfelf, there might have 

 been a faving of a large male apparatus ; but as 

 this is not fo ordered by nature, but each fnail and 

 worm receives and gives impregnation, it appears, 

 that a pleafurable excitation feems alfo to have been 

 required. 



'1 his wonderful circumftance of many infecls be- 

 ing hermaphrodites, and at the fame time not hav- 

 ing power to impregnate themfelves, is attended to 

 by Dr. Lifter, in his Exeicitationes Anatom. de 



VOL. I. Q^q Liinacibus, 



