Sect. XXXIX. 6. 3. GENERATION, 



and not by fexual generation, that there would not at this time 

 have exifled one thousandth part of their p'refent number of fpe- 

 cies *, which have probably been originally mule-productions ; 

 nor could any kind of improvement or change have happened 

 to them, except by the difference of foil or climate. 



3. I conclude that the imagination of the male at the time 

 of copulation, or at the time of the fecretion of the femen, may 

 fo affect this fecretion by irritative or fenfitive aflbciation, as 

 defcribed in No. V. 1. of this fection, as to canfe the produc- 

 tion of fimilarity of form and of features, with the diftinction 

 of fex; as the motions of the chiffel of the turner imitate or 

 correfpond with thofe of the ideas of the artift. It is not here 

 to be underftood, that the firft living fibre, which is to form an 

 animal, is produced with any fimilarity of form to the future an- 

 imal ; but with propenfities, or appetences, which fhall produce 

 by accretion of parts the fimilarity of form, feature, or fex, cor- 

 refponding to the imagination of the father. 



Our ideas are movements of the nerves of fenfe, as of the 

 optic nerve in recollecting vifible ideas, fuppofe of a triangular 

 piece of ivory. The fine moving fibres of the retina act in a 

 manner to which I give the name of white ; and this action is 

 confined to a defined part of it ; to which figure I give tli£ 

 name of triangle. And it is a preceding pleafurable fenfa- 

 tion exifling in my mind, which occafions me to pro- 

 duce this particular motion of the retina, when no triangle is 

 prefent. Now it is probable, that the acting fibres of the ulti- 

 mate terminations of the fecreting apertures of the vefTels of 

 the teftes, are as fine as thofe of the retina ; and that they are 

 liable to be thrown into that peculiar action, which marks the 

 fex of the fecreted embryon, by fympathy with the pleafurable 

 motions of the nerves of vifion or of touch ; that is, with certain 

 ideas of imagination. From hence it would appear, that the 

 world has long been miftaken in afcribing great power to the 

 imagination of the female, whereas from this account of it, the 

 real power of imagination, in the act of generation, belongs 

 folely to the male. See Sect. XII. 3. 3. 



It may be objected to this theory, that a man may be fuppof- 

 ed to have in his mind, the idea of the form and features of the 

 female, rather than his own, and therefore there fhould be a 

 greater number of female births. On the contrary, the general 

 idea of our own form occurs to every one almoit perpetually, 

 and is termed confcioufnefs of our exigence, and thus may ef- 

 fect, that the number of males furpaffes that of females. See 

 Sect. XV". 3. 4, and XVIII. 13. And what further con- 

 firms this idea is, that the male children moil frequently 



Vol. I. E e e re&mhji 



