The doctor has divided his work into fix chapters, in the firft of which he confiders the feveral opinions of authors concerning the propagation of animals and vegetables. He lays before his readers the various conjectures of the learned concerning the vis plaftica, and the use they have made of it to folve their difficulties in accounting for many of the phænomena of nature; and points out briefly the advances made towards the truth by the great Harvey and the members of the Lynnæan academy, 'the hiftory of the foundation and members of which he informs us that he intends foon to publish. After this he proceeds as follows.

After what this great author (Harvey) had produced upon the fubject, it is fomewhat ftrange to find authors now talk of an admixtion of feminal matter of both male and female to produce an offspring; but it would have been a prudent ftep, in such as affert this doctrine, to point out how and where fuch an admixtion can be made, before they advance fuch a notion. Every real anatomift knows that the uterus in human bodies, in a virgin ftate, is very fmall; that its fubftance is very thick, and consequently that its cavity, which confifts only of two little angular furfaces lying close together, is fo fmall and inconfiderable, as not to be capable of containing even a few drops of any kind of fluid. Again, it plainly appears by the ftructure of the cervix uteri, that nothing was ever intended to pass from without, that is, from the vagina, into it; because it is extremely narrow and pretty long, and has glands within, to afford a strong mucus; and ftria and wrinkles to which this matter adheres, in order to fecure and stop up the paffage from even the ingress of the air. That therefore the little foetus must come into it fome other and indeed nature has kindly provided two, which are the fallopian tubes; and that these are the only ways cannot be denied, because we sometimes find fœtufes in these tubes, which, altho' they are contained in ova, very minute globules, when they are first detached from the ovaria, often lie there, and grow very large, when once obstructed in their paffage towards the uterus; and these are what is called extra uterine conceptions; of which several authors have given various

accounts.

way,

• This being the cafe beyond contradiction, the fæcundation of the ova must be made in the ovaria, which can. not poffibly be from an admixtion of grofs feminal matter, because none can arrive at the ovaria by any means; for

if

if the os tince and cervix uteri were quite open so as to admit that grofs matter into it, yet no given force could send the leaft particle into the fallopian tubes, the ingrefs of which into the uterus is fo fmall, as to escape the niceft attempts to find their holes, or paffage from the uterus into the tubes; and are fo contrived as not to fuffer even wind to pass out. And indeed it is with much difficulty that it can be forced open from the tube into the womb. And even in the very last month of pregnancy, when it is diftended to its utmost extent, yet thefe holes or paffages are still clofe; and as, the more the bladder is filled with urine, the closer are the paffages into it compreffed, in order to hinder a regurgitation of the urine into the ureters; fo the preffure of the membranes that contain the foetus upon the valves of thefe holes, together with the natural clofe ftructure of the holes themselves, render them as ftraight as they were, when the uterus was in a virgin ftate, notwithstanding the great diftention it fuffers, during the time of gestation.

Hence we may boldly conclude, that none of the vifible grofs feminal matter that is injected by the male, can ever enter the uterus, and that, upon the firft exercise or motion of the female, it is rejected, and falls out of the vagina, seemingly in the fame quantity as it was injected; and confequently that there can be no affemblage of that matter of the male with any pretended Jemen of a female, on any account whatsoever. Our great Hervey knew this very well, by his frequent infpection of other animals as well as the human; it is therefore much to be wondered, that neither what the learned members of the Lyncæan academy had obferved, the hints given by Hieronymus Fabritius, and the further most fagacious obfervations of the ever famous Hervey, fhould be fufficient to prevent such inadvertent relapfes into the notions of invefting matter with the leaft power of difpofing and directing itself, or of the most remote probability of any admixtion, as is before often mentioned; or that the knowledge of the ftructure of the parts of animals, ferving to their procreation, is not of force enough to prevent authors from running back into those obfcure and unintelligible systems, which the learning and fagacity of the glorious writers above mentioned had taught them to fhun.

Now no fluid of the female can come into the vagina, at the time of the coit, but from the lacune; and it is this which is destined only to lubricate the paffages, and caufe much of the fenfations proper to the occation in paffing thefe lacuna; but, if we would fuppofe that lubricating Vol. VI.

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Auid

fluid to be feminal, yet to what purpose could it ferve, when it must be carried off out of the vagina, together with the fpermatic juice of the male, upon the first motion of the female? Again, if it be pretended that the little ova in the ovaria contain feed, how can it come down to meet that of the male, and where can it be retained? Not in the uterus, for the natural reafons above mentioned; not in the vagina, for whatever is thrown in there, is abfolutely ejected in a few minutes after; and this leads me to the defcription of the ovum that comes into the womb of a viviparous animal, whatever may have been faid to the contrary, by thofe who have not been happy in frequent opportunities of viewing and confidering these things, nor are poffeffed of the neceflary qualifications for making fuch obfervations on animal bodies.

'An ovum of a viviparous animal confists of parts containing and fuch as are contained. Those containing are membranes, the chorion and amnion; the chorion is the external, having, on a part of its furface, the placenta in its rudiments, which are the radiculi of the parts contained. The amnion is the internal, on whofe furface the veins and arteries appear proceeding from the little radiculi, and at laft uniting to form two arterial trunks, and one large vein : which three veffels, being inveloped in a mucous cafe, formed out of the membranes, make together the umbilical cord, at the extremities of which the little organization of the fœtus grows, and thefe, together with the waters that inviron the foetus, are the parts contained.

This is the true ftate of an egg, as it grows from its hold in the ovarium, in its moft minute ftate ; and it is exactly the fame without the leaft alteration, even in the last month of pregnancy in the womb. Now to wound or break these membranes by any means, which reprefent a bladder full of a fluid, would be to let the fluid out; this done when minute in the ovarium, the membranes collapfe, and the little organization perifhes. And thus, after an eggi has paffed the tube, and has got into the uterus, if by any accident the membranes break, the waters run off, and an abortion muft inevitably follow, at any time of pregnancy: and, in a word, thus at the completion of the time of pregnancy, when labour comes on, the child commonly foon follows the breaking of these waters. Hence, one may naturally conclude, nothing can pass through these membranes of any kind whatsoever, without destroying them.

• That

That this is the cafe, every one duly verfed in these things must confefs; what then can infatuate any one to imagine, that the liquor amnii, in the little ovum, should be feminal matter, any more than it is fo, when the ovum is ready for the birth? Where is it poffible for an admixtion to be made between the grofs male fperm and this little liquor amnii; and to what purpose could it ferve, if they could come together?'

In the fecond chapter our author proceeds to lay down his own opinion of the manner of the propagation of animals and vegetables, by primary organizations. He introduces it with obferving, that the doctrine of concreation ferves only to perplex the beautiful order and fimplicity that is obfervable in the feveral advances of the great work of propagation; and that every animal and vegetable, at its first creation, was only made capable of bringing forth its offspring according to its kind, in a fucceffive feries, from age to age, by the divine author, each kind being confined to its own certain limits of form, features, tafte, fmell, and all other qualities and characters, which the Almighty FIAT had at first impreffed upon it; beyond which it cannot go, and from which it can never alter effentially. After this he proceeds as follows.

The uniformity of ftructure and encrease between animals and vegetables is very aftonishing; and the order and œconomy, in which they are carried on, are amazingly alike; and, however oppofite fome ingenious men may be to any endeavours to account for the phænomena that relate to it by their analogy, opinions are free, and in many other things as well as this, he that has no opinion of his own, feems not to bid very fair for making an improvement in natural knowledge. The chain of my arguments, through this litttle work, fhall be carried on link by link, in fearch of the mystery of propagation by analogy. It is by this, and the many visible facts attending it, which are so glaring and plain to the view of every impartial obferver, that I do not doubt being able to bring many truths to light which muft inevitably have lain hid for ever, if not fearched for through this channel of analogy.

To begin then, let us firit take a view of the eggs and feeds of animals and vegetables, which are fubjects obvious and plain to every one's fentes; and from which we can fee animals and vegetables grow before our eyes in their proper feafons, and according to their kinds; and which no one can deny, without calling his own fenfes in question. And

fecond

fecondly, let us go a little back, and endeavour to fhew, how thefe eggs and feeds come to be formed and made complete and fit to be treasured up, in order to their further propagation at any proper time.

In the animal fyftem the roes of fifshes, the eggs of insects, and those of all kinds of birds, and all other animals, are alike in all respects. They are for the most part roundish compact bodies, or of fuch convenient determinate forms as fuit their natures; they all having teguments nobly contrived for their prefervation; those designed for extrusion, and to be preserved out of the body, with hard or otherwise very compact coverings, to fecure them from external injuries; thofe to be treasured up in the body, with their proper coverings alfo, but foft and membranous, as being already fafe enough from any external dangers. Every individual kind contains its own peculiar fubftances, always differing fpecifically from that of every other kind in tafte, and all other qualities and refpects. All these characters are proper alfo to feeds of every kind; they have their natural coverings, more or less compact, according to their neceffities; their forms are complete and convenient; the fubftances they contain are also peculiarly and fpecifically different from those of each other, in all their qualities; and their offspring proceeds from them in the fame manner as animals proceed from their parent eggs.

Thefe are truths which we may presume no body can deny; to which we must add another as evident, and that is, that, befides the feveral fubftances faid before to be peculiar to every feed, there is alfo a peculiar organization treafured up in each, which is no other than the rudiment of the future tree or plant, capable of being propagated into fuch a tree or plant as it fprung from, and no other, according to its kind. If this be doubted, here are many evidences to prove it: the feed of the acer maximum contains in its pod, which is lined with a fine filky down, a plantula of a confiderable bignefs, confifting of a pedicle and two long leaves, each about three quarters of an inch long, between which, the vifible bud of another part of the organization appears ready to be propagated. In every one of the nut kinds, and all the fabaceous and pulfe kinds in general, there is a visible organization peculiar to each species, treasured up in the fame integuments, together with the other fubftances proper to it (of which we fhall fpeak more in the fequel of this work) and, in a word, the most minute feeds whatsoever are furnished with their little organizations, however minute they may be. Surely, when fuch organizations ap.

pe ar