SECT. XXXIX. 7. GENERATION. 597 



fhoulders, or fuch as conftitute certain hereditary 

 difeafes, as icrophula, epilepfy, infanity, have their 

 origin produced in one or perhaps two geneiations; 

 as in the progeny of thole who drink much vinous 

 fpirits; and thofe hereditary propeniities ceafe again, 

 as I have obferved, if one or two ibber generations 

 fucceed ; otherwife the family becomes extinct. 



This living filament from the lather is alib liable 

 to have its propeniuies, or appetencies, altered :\t 

 the time of its production by the imagination of the 

 male parent; the extremities of the feminal glands 

 imitating the motions of the organs of fenfe ; and 

 thus the fex of the embryon is produced ; which 

 may be thus made a male or a female by affeding 

 the imagination of the father at the time of impreg- 

 nation. See Sedl. XXXIX. 6. 3. and 7. 



7. After the fetus is thus completely formed to- 

 gether with its umbilical veflels and placenta, it is 

 now fupplied with a different kind of food, as ap- 

 pears by the difference of coniiftency of the differ- 

 ent parts of the white of the egg, and of the liquor 

 amnii, for it has now acquired organs for digeition 

 or fecretion, and for oxygenation, though they aie 

 as yet feeble ; which can in fome degree change, as 

 well as felcdt, the nutritive particles, which are nou' 

 prefented to it. But may yet be aifected by the 

 deficiency of the quantity of nutrition fupplied by 

 the mother, or by the degree of oxygenation fup- 

 plied to its placenta by the maternal blood. 



The augmentation of the complete fetus by ad- 

 ditional particles of nutriment is not accomplished 

 by diftention only, but by apportion to every part 

 both external and internal ; each of which acquires 

 by animal appetencies the new addition of the par- 

 tides which it wants. And hence the enlarged paits 

 are kept iimilar to their prototypes, and may be 

 faid to be extended ; but their extenfion muit be 

 conceived only as a neceffary confequence of the 



enlargement 



