HISTORY OF THE FERTILIZATION PROBLEM 3 



he descended deeper into the slough of metaphysics than 

 Aristotle, and committed himself to the fantastic idea 

 that conception in the uterus is identical with, or at 

 least analogous to, conception in the brain; and that the 

 ovum is the product of such unconscious uterine desire 

 or conception, and receives no material substratum from 

 the male! 1 The theory of reproduction was no whit 

 more advanced in the middle of the seventeenth century 

 than in the time of Aristotle. 



The use of the microscope in biological research 

 began in the seventeenth century; it was the improve- 



1 "Since there are no manifest signs of conception before the uterus 

 begins to relax, and the white fluid or slender threads (like the spider's 

 web) constituting the *' primordium ' of the future 'conception' or ovum, 

 shows itself; and since the substance of the uterus, when ready to con- 

 ceive, is very like the structure of the brain, why should we not suppose 

 that the function of both is similar, and that there is excited by coitus 

 within the uterus a something identical with, or at least analogous to, 

 an 'imagination' (phantasma) or a 'desire' (appetitus) in the brain, 

 whence comes the generation or procreation of the ovum. For the func- 

 tions of both are termed 'conceptions,' and both, although the primary 

 sources of every action throughout the body, are immaterial, the one of 

 natural or organic, the other of animal actions; the one (viz., the uterus) 

 the first cause and beginning of every action which conduces to the 

 generation of the animal, the other (viz., the brain) of every action done 

 for its preservation. And just as a 'desire' arises from a conception of 

 the brain, and this conception springs from some external object of de- 

 sire, so also from the male, as being the more perfect animal, and, as it 

 were, the most natural object of desire, does the natural (organic) 

 conception arise in the uterus, even as the animal conception does in the 

 brain. 



"From this desire or conception, it results that the female produces 

 an offspring like the father. For just as we, from the conception of the 

 'form' or 'idea' in the brain, fashion in our works a form resembling it, 

 so, in like manner, the 'idea' or 'form' of the father existing in the uterus 

 generates an offspring like himself with the aid of the formative faculty, 

 impressing, however, on its work its own immaterial 'form" (from 

 William Harvey, "On Conception," 1651). 



