397 



CCVII. Of gestation. From the moment of conception, there begins 

 in woman, both in the motion of the solids, and the composition of the 

 fluids, a remarkable alteration. The change that has taken place shows 

 itself in all her functions: she exhales a peculiar odour; the child she 

 suckles refuses the breast, or takes it with reluctance, an$ soon falls away, 

 if left in the hands of such a nurse. 



Nature, occupied with her work, seems to forget every thing else, to 

 bring it to perfection. It has been observed, that in times of contagious 

 diseases, even where the plague raged, pregnant women were least ex- 



tube to the cavity of the uterus. They further proved, that previously to impregnation 

 nothing like a germ could be found even in the real egg's, but that there is placed on 

 the vitellus, a small vesicle, the cicatricula, containing a fluid of the same nature, and 

 destined for the same end as that in the vesicle of the ovary. The only difference, 

 therefore, in this respect, between the egg and ovary, according to this sect, is, that 

 the former has a single, while the latter has a cluster of vesicles. 



By this doctrine of spermatic worms, which completely usurped the place of the ovu- 

 lar doctrine, and which acquired for a time an undisputed ascendency in the medical 

 and philosophical schools, it was affirmed, that these seminal vermiculi are living minia- 

 tures of the animal from which they are derived, exacting only from the female a ma- 

 trix for nourishment, evolution and growth. 



Though the ovular doctrine was thus subverted by Lewenhoek and his auxiliaries, it 

 after a while again revived, under the auspices of Haller, so far at least, as to suppose 

 the pre-existence of a germ in the female, and soon received the distinguished support 

 of Bonnet, Spallanzani, Hunter, &c. Being restored in a more enlightened age, it of 

 course was stripped of most of those extravagancies which had before detracted so 

 much from its merit. Agreeing in the fundamental principle of the doctrine, these 

 physiologists entertained some difference of opinion as to the origin, the existence and 

 develop ement of the germs. They all, however, maintained that the germ, as the 

 exact miniature of the animal or vegetable to which it belongs, exists in the female 

 prior to fecundation, requiring only the stimulus of the male seed to excite it into life, 

 &c. 8cc. 



By thus narrowing 1 the definition of the doctrine, they presented it in a guise exceed- 

 ingly alluring, and rested its vindication on a collection of experiments and observa- 

 tions, in appearance, the most definite and conclusive. These, however, on a closer 

 examination, exhibit a very different aspect, so much so indeed that a large number of 

 distinguished physiologists have been induced, upon the most diligent scrutiny, to 

 question altogether the pre-existence of germs. It would be wholly inconsistent with 

 our limits to detail the arguments and reasonings which have been employed by the 

 adverse parties in this interesting controversy. We proceed next, therefore, to the 

 doctrine of Epigenesis. 



Discarding, as we have already hinted, the notion of the pre-existence of germs, it 

 presumes that " the prepared, but at the same time unorganized rudiments of the foetus, 

 first begin to be gradually organized when they arrive at their place of destination, at a 

 due time, and under the necessary circumstances." This is the definition of a learned 

 writer. The doctrine, however, may be more distinctly enunciated. We would say, 

 that, denying the pre-existence of germs in either parent, the doctrine of Epigenesis 

 supposes, that the fluid contained in the ovarian vesicle is the rude elementary matter, 

 which, after impregnation, becomes organized into an embryon by the energies of the 

 semen masculinum. The primary traces of this doctrine are to be niet with in the 

 writings of Aristotle. The prevailing opinion on the subject of generation, in the time 

 of this eminent philosopher was, that each sex furnishes semen, and that the embryon 

 results from an admixture of the two fluids in the cavity of the uterus. After confuting 

 the popular idea of women having semen, he asserted" that they contribute nothing to- 

 wards conception, except the menstrual blood ; that the rudiments of the embryon are 

 derived from the menses, and are vivified and put together by a plastic power, which 

 he imputed to the semen. With various modifications this hypothesis has been handed 

 down to us. It would be tedious and impossible to point out all the shapes which at 

 different times it has assumed. Of late its most able and determined supporter is Bin- 

 menbach, to whose system of Physiology, and Essay on Generation, we must refer such 

 of our readers as are desirous of further information on this subject. Chapman. 



