After distinguishmgthe true from the probable, an indispensable duty 

 in every science of facts and observations, like physiology, I shall pro- 

 ceed to state the hypothesis, which appears to me the likeliest, on the 

 manner in which the two sexes concur in the production of the new 

 being. 



CCV. The foetuses pre-exist in the ovaria of the females, not that they 

 are there since the creation of the world, as Bonnet believed, and all who 

 embraced the doctrine of that metaphysical naturalist j but the ova con- 

 taining his germs are formed by the proper action of the ovariutn which 

 secretes them, a fresh proof that all the phenomena of organized bodies, 

 whether for the preservation of the species or of the individual, are effect- 

 ed in the way of secretions. This ovum, produced by the elaboration of 

 the blood which the spermatic vessels carry to the ovaria, contains the 

 lineaments of the new being ; but it is only the sketch, or carcass of it, if 

 this may be applied to what has not yet lived. The seminal fluid must 

 bring it out of this state of inactivity, and, with something of an electri- 

 cal power, waken it into life. The eggs laid by a maiden hen, will never 

 hatch, though there are in them the rudiments of the chick. The eggs 

 of a frog that has been kept apart from the male, during the whole time 

 of spawning, putrify in the vessel of water they are kept in: if the male, 

 on the contrary, if sprinkled with his semen, as they quitted her, they 



is adapted to this office. It is almost as well ascertained that they convey nothing- from 

 the uterus, and the orifice is fashioned accordingly. 



By assigning to the tube this function, we moreover invest it with a power of a two- 

 folti action, precisely opposite, of which there is no analogy in the animal economy. The 

 inverted periastalic motion of the intestines, comes nearest to an example, but it will 

 not hold. The cases are not parallel, the action of the intestine being preternatural, 

 the effect of violence and disease. It is useless, however, to protract this discussion, as 

 we have proof at hand which is absolutely conclusive. By the experiments of Mr. 

 Haighton, it is ascertained that the tubes do not change their position to grasp the ma- 

 tured vesicle till the whole process of conception is consummated in the ovary. 



"I found," says this eminent physiologist, " from a series of observations made on 

 different rabbits, at every hour between the 1st and 9th, that the iimbrix remained 

 nearly in their usual situation, and the only difference 1 found in the last hour, was a 

 greater turgescency of vessels, as if preparatory to some important action. I desisted 

 from this inquiry at the 9th hour, because the ovaries bare evident marks of impregna- 

 tion, and there appeared to be no action in the tubes, by which the semen could be 

 conveyed to them." 



Convinced that the hypothesis in its primitive shape was no longer tenable, some of 

 the advocates of impregnation by contact, have contended that it is effected by the 

 emission of subtle exhalation from the semen, termed aura semitiaUs, and which is trans- 

 mitted through the tubes to the ovary. But here they are again met by the whole body 

 of facts, and chain of reasoning which drove them from their original position. It has 

 indeed, been said, and with no want of plausibility, that the volatile vapours from the 

 semen might penetrate through obstructions which should resist the semen itself. Be 

 it so : in many instances, it might happen undoubtedly. But still, how can the cases 

 formerly referred to, be got over, where from organic derangement, the passages were 

 so entirely occluded, as to be impervious even to air ? 



Nor are these the only difficulties that stand in the way of this amended hypothesis. 

 We are not disposed, however, to enter at present into any further detail. Before we 

 engage in a lengthened investigation of this sort, we require it to be shown that the 

 aura seminalis has the property of fecundation. As yet, no such proof has been exhibi- 

 ted, The experiments of Spallanzani, and Hunter, the only ones which have been made 

 on the subject, prove indeed quite the contrary. Chapman. 



Dr. Gartner of Copenhagen has demonstrated the existence of ducts leading from 

 the ovaries to the uterus in the cow and sow, Dr. Dewees of Philadelphia, some years 

 ago published a new theory of generation, which is predicated on the existence of these 

 ducts between the vagina and ovaries. See ed. Med. Journal, July 1822. Godman. 



