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the ovarists, that the seed of the male contains a multitude of spermatic 

 animalcules, all capable of becoming 1 , by developement, beings similar to 

 their father. These animalcules push forward, along the tubes, upon the 

 ovaria : there a general engagement takes place, in which all are slain, 

 save only one, who, master of the field of battle, finds the triumph of his 

 victory within the ovum that has been prepared for him. This system, 

 \vnich is not the most probable in the world, assigns to the male the 

 greater part in the work of generation, since the female is made to fur- 

 nish merely the coverings of the foetus. 



It would be to no purpose to unfold, more at large, opinions hazarded 

 on a subject so obscure. What I have said is enough to show that those 

 parts of nature which most obstinately elude our curiosity and afford 

 most scope to our imagination, are those whfch men believe they know 

 the best, and on which they speak with most confidence and prolixity: 

 so true is it, as Condillac has observed, that we have never so much to 

 say, as when we set out from false principles*. 



* Numerous as are the theories which have been advanced on the subject of gene- 

 ration, they may all, as mere varieties, (or at least such as are worthy of attention,) be 

 very properly reduced under two leading heads or general divisions. 



1. Doctrine of Palengenesis. 



2. Doctrine of Epigenesis. 



The first of these doctrines suppose the pre-existence of germs. It is of great anti- 

 quity, and in its descent to us has undergone some slight modifications- By most of 

 the early philosophers it was taught, " That these germs created with the beginning 

 of things, were scattered throughout the world, but ultimately meeting- with appropri- 

 ate genital organs, effected a lodgment therein, and became fit for developement." 



As soon, however, as the moderns entered into speculations of this nature, the hypo- 

 thesis received a correction which, in part, divested it of its absurdity. Denying- that 

 these germs wandered about " in quest of an habitation and a home,'*, it was now, on 

 ;he contrary, maintained, " That all of the same species, were ab initio neatly incased, 

 one within another, so that the first parent, animal and vegetable, contained the germs 

 of each succeeding- generation, and which to be evolved required only the seminal im- 

 pulse of the male." 



This doctrine of evolution had been hardly revived, when two sects arose, who urged 

 their respective opinions with all the zeal, all the ardour, and all the pertinacity of 

 party controversialists. They differed, however, only on a single point. By the one 

 side it was maintained, that the germs were furnished by the female, and by the other 

 that they proceeded from the male. 



The former of these opinions was brought into repute by Fabricius ab Aquapendente, 

 so called from the place of his nativity. Having- ascertained, as he thought, by a series 

 of experiments on the eg-g, that it contained a pre-existing- embryon, he, with a nume- 

 rous train of disciples, pushed their investigations, and finally detected, or pretended 

 to detect, ova also in the viviparous animals. 



Enamoured of this boasted discovery, the celebrated Harvey became one of the 

 warmest and most strenuous supporters of the hypothesis to which it led. " Omnia ex 

 ovo." 



This brief aphorism, which escaped from him in the enthusiasm of his devotion, suf- 

 ficiently marks his impressions on the subject. The only distinction, indeed, which 

 he admits in the generative process of the two classes of animals, is, ** That in the vi- 

 viparous, the feet us begins to exist, increases, and completes its growth in the uterus; 

 whereas, in the oviparous, the embryo exists in the egg in the body of the hen, but 

 does not become a fccttts till expelled, and is hatched into life by incubation." 



The ovular doctrine was first arranged by Lewenhoek, Who made the discovery of 

 the spermatic animalcules in the male seed- By him and his followers, the existence 

 of ova in viviparous animals was speedily and satisfactorily confuted. They demon- 

 strated to entire conviction, that what had been taken for true ova were the mere vesi- 

 cles of the ovary, which have no resemblance to an egg, being merely cups or reser- 

 voirs of a fluid, which after fecundation is discharged and conveyed by the fallopian 



