s>#l\^ Vtr Digitized by the Internet Archive in 2011 with funding from Open Knowledge Commons and Harvard Medical School http://www.archive.org/details/observationsuponOOneed 'SEl V>5»'"- Jr OBSERVATIONS upon the GENERATION, COMPOSITION, and DECOMPOSITION of ANIMAL AND VEGETABLE SVBSTANCES. communicated in a letter to Martin Folkes Efq; Prefident of the ROYAL SOCI ETY by TVRBERVILL NEEDHAM Fellow of the fame. L O N T> O N: Printed in the Year MDCCXL1X. ito Bsi >& A Summary of fome late Obfervathm upon the Generation, Compofition, and Decomposition of Animal and Vegetable Subftances ; Communicated in a Letter to Martin Folkes Efq\ Prejident of the Royal Society, by Mr. Turbervill Needham, Fel- low of the fame Society. Paris, Nov. 23, 1748, N. S, SIR, § 1. r I ^HO' I think myfelf now almoft fufficiently 1 qualified, by the Multitude of Experiments I have already made upon animal and vegetable Sub- ftances, fince the 16th, -N. S. of laft March, to lay down fome certain Truths upon this Subject, and from them to advance, by Induction, farther than fo fhort a Period of Time would allow me to proceed by fpecial Experiments, yet I would have your learned Royal Society look upon this Paper as animperfect Sketch-only of what I hope topublifh from the Journals I have by me in a few Months, if thefe two or three Sheets are fo fortunate as to meet with their Approbation. lam fufficiently feniible how much 1 may hurt this little Performance, if I promife too much, and raife in this Matter higher Expectations from the Public than it may appear hereafter to deferve : It is at this time therefore particularly the more neceflary, that I mould be exceedingly cautious to advance no Propo- rtion rafhly i nothing, but what feems to flow natu- rally from Obfervation. But this Precaution, however * drift, [2] ftrict, will not exclude now-and then a probable Confequence from appearing, provided it feems con- nected with fome preceding manifeft Truth; for fuch muft be allow'd, as proper Foundations for a more exact Inquiry in a Matter I am very far from pretending to have exhaufted. I muft therefore ob- serve, for my own Security againft future Objections, that tho' I add no new decifive Experiment to my prcfent Lift, or throw any more Light upon the Subject than what I have already amaffed, I may poflibly, before my EfTay appears, whether by the Advice of Friends, or otherwife, conceive more mature Thoughts, reject fome of the prefent, and adopt others in their Place. As this will be done, without affecting in any degree the main Syftem, which I imagine turns upon unquestionable Truths, it is a Liberty I am perfuaded that equitable and learned Society will indulge me in, if no other Confideration prevails, than the great Oblcurity that hangs over a Subject fo extenfive and fo intricate as this is ; in which I am already engag'd much farther than I at firft forefaw, and indeed too far to recede without faying fomething. § 2. 1 (hall take as little Notice as may be, in this fhort Summary, of the almoft inevitable Mif- takes others may have made in this Matter be- fore me, and the too hafty Confequences they have drawn from Appearances that naturally furprife by their Novelty. Such Surprize is but too apt to cap- tivate Perfons even of the moft ferene Thoughts, much more the young and unexperienced s fuch as Mr. Hartfoeker was, when he firft difcover'd the fpermatic Animals. $3- [3] § 3- Mr. Lewenhoeck indeed, fo near his Cotem- porary in this Difcovery as to claim a Priority, was much more advanced in Age and Experience ; yet if he mould alio appear to have been miftaken, wc are not to be furprifed at it; for his repeared Ob- fervations upon the Sperm of fuch a Variety of Ani- mals, even as low as Infeds, fcemto intitle him to draw Confequences as extenfive for a general Syf- tem of Generation, as his Experiments had been. In effect, what two more powerful Arguments could a Philofopher with the Knowledge of no other Fad, than that of their Existence, have, than the Univerfality of Animalcules in this Fluid, and their feeming Confinement to this animal Secretion? § 4. The Method of Reafoning by Analogy is but too apt to lead us into Miftakes, and therefore we ought to be very diffident of Confequences deduced this Way. Every new Appearance that has no known Caufe, immediately fixes, and but toooften at laft puts the Thoughts of the Obferver upon the Rack, When the Mind arrives at this Intenfity of Adion, how natural is it to free ourfelves from a painful Un- certainty at any rate, and that with as little Expence of Refledion as may be I The mod obvious and eafy Method is to clafs, if it admits it, and to re- duce It to fome other known Phenomena ; poffibly we are yet no nearer the phyikai Caufe, becaufe that of both is unknown. We have ftill, however, the Satisfadion to have diminifhed the Surprize it gives, by taking from its Singularity, and reft in fome meafure contented with this little Deceit. § 5. I call it a Deceit, if we acquiefce in it, tillfuch time as a Number of Circumftances mail concur to * 2 place [4] place it above the State of an Hypothecs, and mew us we have been right in our Inferences. Mere Ana- logy, founded only upon one or two Fads, and extended by Conjecture, however plaufible, can but at moft furnifh Motives for a reafonable Doubt, and a more mature Enquiry. For thoJ, as a modern Au- thor obferves very well, Nature feems every-where to hold with itfelf, and go off by an almoft imper- ceptible Gradation j yet, in our prefent Ignorance of the entire Chain of Beings, we are fo liable to miftake two diftant Species for the next immediate ones to each other, that the Analogy is thereby nearly extinguifhed, and its Traces almoft effac'd. § 6. That this has been too much the Cafe in all the modern Syftems of Generation, will appear I believe plain in the Courfe of this Memoir to every un- biafs'd Naturalift. Animalcules were found univer- fally in all animal Seed, almoft at all times, and feem- ingly in this animal Secretion alone 5 they were therefore previoufly thought eftential to Generation _j or they mould have added, a neceffary Confequence of Properties in the Sccdj which Properties were eftential to Generation. But this Inference, how- ever natural, was intirely overlooked by them in their Reafoning 5 and Analogy indue d them to ftop at the firft, without ever examining the fecond, tho' equally confequent. The Opinion of pre- exiftent Germs had prevail'd, under the Notion of Female Eggs, ere this Difcovery was made; and thus one Miftake had been grafted upon another. When the fpermatic Animals appeared, it was not difficult to transfer thefe imaginary Germs from the one to the other ; and at moft Philofophers were only [5] only divided by it; tho' as both Opinions were equally plaufible, the latter generally prevailed by its Novelty. The vaft and unbounded Profpect it open'd to the Imagination, in a View of fuch a prodigious Series from the firft Parent to the laft, of original Linea- ments, ftruck the Mind with an agreeable Surprize. The Folly of equivocal Generation, particularly as it had been ftated by the Antients, the falfe Grounds they had proceeded upon to eftablifh it, various Ex- periments that feenfd to prove every Animal, every Plant, defcended from Individuals of the fame Spe- cies 5 but, above all, the Facility of claillng thefe fpermatic Animals, the reducing them by Analogy to Seed and Eggs, and the known Tranfition of moil Infeds from one State to another, feem'd all fuf- ficient to remove the Veil Nature had drawn, and furnifh a Clue of a competent Length to conduct us into its mod hidden RecefTes. § 7. Thus this new Syftem of Generation foon be- came a favourite Opinion of the laft Age, as it is in- deed ftill of this for the molt part ; and many ingenious Methods were imagined of anfwering the Difficulties from Obfervation that feem'd to oppofe it. The more antient Hypothecs of female Eggs was at laft blended with it, and both were work'd up into one Syftem : Their real Exiftence was determined, with their Form, Colour, Size, Situation, and the Me- chanifm of their Conveyance to the Womb; and imaginary Valves v/ere appointed in each Egg ad- mitting one, exclufive of every other fpermatic Animal. Happy the firft of thefe minute Beings that could take PofTeilion of this little Cell, and {hut the Door againft contending Millions ! Hi- therto [6 1 therto every Step feemed eafy and natural, if not too clofcly examined ; the lnquifitive were con- duced as high as their Curiofity could promife; and we might have expected, that Philofophers Ihould have ftopp'd here? but there is no End of reafon- ing by Analogy. § 8. No Body of Men fo ftri&ly dcfcrves the Name of a Republic as that of the Learned does : Every one is pafllonately fond of adding to the common Stock, and claims nothing in Return, but the Name and Merit of having enrich'd it ; yet this Paffion is often fo violent, that bafe Metals are miftaken for Gold, and Pebbles for Diamonds. It is not therefore Matter of much Surprize, if fome have carried the imaginary Scene yet farther ; and,flill pro- ceeding by Analogy, have fuppofed that the reticular Expanfion, obferved in the Womb of Docs fome Days after Copulation, by Harvey, and ftnee him, in other impregnated Females, was nothing more than the inverting Web, fpun by the fpermatic Ani- mal before it enter'd the chryfalidal State, and pre- paratory to its Transition from one Form to ano- ther. Certainly thefe Authors never confider'd the immenfc Difproportion, between the great Expan- fion of this Web and the inconceivable Minute- nefs of the Animalcule 5 otherwife it had appeared as rational to fuppofe, that an Alpine Mountain could have been rear'd in a few Days by a Tingle Emmet fucceflivdy pileing one Grain of Sand upon another. Nothing now feem'd wanting to com- plete this Syftem, and place it above all Exception, but ocular Demonstration, if it might poflibly be obtained, that the original Embryo was really con- tained [?] tained in each of thefe Animalcules : By DhTec*tion, the young Butterfly had been obferved in the Ca- terpillar three or four Days before it became a Chryfalid ; Mr. Lewenhoeck had fucceeded in fome other very nice Operations upon extremely minute Subjects, nor did he defpair of his Succefs in this ; yet his repeated Attempts, it feems, all proved fruit- lefs. But what the moft exquifite Art had deny'd to Lewenhoeck, Chance, if we believe him, presented to another Naturalift, a little Man ftarted from under the Integuments he was faid to wear in his vermicular State; and the Obferver very humour- oufly gave us a Figure of this diminutive Entity perfect in every Member. Thefe extraordinary Sallies, however, we muft not place to the Ac- count of the Learned, either of this or the laft Age; they were generally exploded, and they indeed continue fo; yet altho' they were peculiar only to the moft lively ; extravagant as they may appear to be, they were Confequences of the Syftem; and thus was this Method of Reafoning by Analogy fairly purfued, as far as Imagination could carry ir. § o. Cudworth, Grew, Le Clerc, and fome other Gentlemen of Judgment, had reflected too deeply upon Nature to give way to any Hypothecs, how plaufible foever, that took in lefs than the whole Scene it exhibits to every attentive Obferver* Yet they feem to have advanced much too far to- wards the other Extreme ; and their Syftem of plaf- tic Natures, tho' in its Detail attended with many Proofs of extenfive Thought, and profound Reflec- tion, in a general View derogates as much from the Omnipotence C81 Omnipotence of an All-wife Creator? and is not perhaps lefs extraordinary, than that Opinion which attributed the Regularity and Motion of the Planets to the Miniftry of Angels. In this Light, I pr^fume, it has been looked upon by others, as well as by myfelf ; and it is upon this account that I imagine it has had fo few Followers 5 I mall therefore take no further notice of it here, than to oblerve, that, in- afmuch as it admits a productive Force in Nature, and Operations that go much deeper than a mere Developement of Parts, it has certainly more of Truth in it, than the Opinion of pre-exiftent Germs: as I flatter myfelf, will appear evident in the Courfe of this Memoir, by Arguments drawn not from Obfervations only, that are obvious to every Natu- ralift, but particular Experiments made upon animal and vegetable Subftances, during the whole Sum- mer of this prefent Year. § 10. To enter therefore more particularly into my Subject, where to place the pre-exiftent animal Embryo, for inftance, whether in the Animalcule or Egg, was ever the Queftion, and ftill remains unanfwer'd. A Diviiion of vital, efiential, and original Stamina or Lineaments was impoflible,- yet innumerable Inftances in Monfters, Mules, and many natural Subjects, concur to prove, that the young Foetus partakes of the Nature, Qualities, Conftitution, Form, and Features of both the Pa- rents j even as far as their Defects and Difeafes, which arc but too often hereditary. How can it then be agreeable to Reafon? Or to what Pu pofe mould we call in to our Aid unalterable original Stamina ? Can the vifible Species of any Production be deter- min'd [9 ] min'd by them, if every fenfible Quality may be in- fluenc'd indifcriminately by cither Parent ? And if they cannot be alter'd, nor the vifible Species be determin'd exactly by them, in what does their Ef- fence coniift, or how can they be applied to that very UTe we feem to think them defigned for ? If they are placed in the Animalcule, or in the Egg, how are they tranfmitted? And if in the Animal- cule, why is the Procels attended with fo vaft an Expence, fo great a Wafte of Millions of Entities, each containing within itfelf a Series of the moll perfect: and mod wonderful Productions in Nature, when one only of thefe Millions of Millions is alone to take Place? How are thefe Animals generated: if in the common Way, not only the Procefs will be boundlefs, and thefe in their Seed have others, and fo on in an immenfe Series; but they can not then. be unalterable, becaufe they are fuppofed capable of being generated. Further, if they float in the Air, or lie hidden in Food, as fome have thought, how is it that the Stamina of one Species do not fometimes infinuate themfelves into a ftranse Parent, with all the Inconveniences and Abfurdi- ties of equivocal Generation ? Or if they are faid to be excluded by proper Strainers adapted for that very Purpofe in diftant Species ; at lead they cannot be fo in thefe Kinds that are near akin: For if the fpermatic Animal, which is naturally pro- ductive of a Horle in its own proper Matrix^ is yet fo fitted to the Eggs of the Afs, that it can poilefs a Cellule there exclufive of every other, which ar- gues an exacl Coaptitude, certainly the fame Animal- cules, if contained either in Food, Air, or Water, common to both Horfe and Afs, might pafs the * * Strainers [to] Strainers indifcriminatcly of cither 5 and thus might we have Mules common from each refpe&ive Male, without a promifcuous Congrefs of thefe two Spe- cies. §11. In another View, if we confider the ex- treme Tenuity, I may fay the mere Nothingnefs of one of thefe Stamina, in its firft Origin, at the Diftance of many Ages 5 comparatively to any one Part, the fmalleft mufcular Fibre, for inftance, of an adult Animal it is now faid to conftitute : how can we underftand, that fo minute a Filament could be developed, or in any Senfe ferve as a Sub- ftratum to a Cylinder fo folid, fo maflive, fo compa- ratively immenfe ? Could a Mountain be look'd upon as a Superftru&ure upon a Grain of Sand ? Or the terraqueous Globe derive its prefent Dimenfions from the Dilatation of an Atom ? What is not the prodigious Force of this mufcular Fibre in its pre- fent State, if compared with what it had in its Origin? and, consequently, what muft have been the Increafe of real extraneous Matter, either by Appofition, or Incorporation ; which is now as much a Fart of this Fibre as the original Stamen ? And if thus much can mechanically be aflimilated, why not the whole of it formed by mechanical Caufes ? Or why muft fo infignificant a Part of it be faid to be concreated with the Univerfe? But to ftrike at once with what, in my Opinion, may be look'd upon as a demonstrative Argument againft the Syftem of original Stamina ? The Difficulty ftill in- creases immenfely, if we look into the Vegetation of Plants, and the wonderful Re-produ&ion of the Parts of Polypes, Starfifri, Lobfters Claws, &c. The original [»3 original Stamina, how minute foevcr, queftionlefs are difFufed through the whole Production; fince in this Syftem all animal or vegetable Growth is made by Developementonly : But if diffus'd, then fome or all maybe by fuccefTive Bifedion loft; and if loft, how can they be reproduced ? Or if reprodue'd, why ever faid to be original, and concreated with the Univerfe? § 12. Thefe are but a few of thofe many Dif- ficulties that might be enumerated j which yet are of fucha Nature, that it is evident to every unbiafs'd Obferver, they cannot be even feemingly evaded. but by multiplying Suppofitions on Suppofitions; which at laft render the Hypothecs fo complex-, as to retain no one Charaderiftic imprefs'd upon the ordinary Procefs and Operations of Nature. Is it not much more reafonable to fay, that fo many fecretory Duds, fo many Strainers, fo many preparatory VetTeis in Animals, andfuch a curious Difpofition in Plants for the Continuation of every Species, imply a Dige- ftion, Secretion, and Preparation of Principles invari- ably, univocally productive of every Individual, when they fall into their refpedive Matrices, and find Aliment proper to ailimilate? Are not thefe Princi- ples contained in the Nourishment taken by the Parent Plant or Animal, the fame that continually vegetate within it, and furnifti it with Materials for its own Increafe ; continue to be diftributed till it becomes adult, then plentifully exuberate, whilft it is, by new Preparations, fitted to propagate invaria- bly in a proper Matrix its refpedive Kind ? Elfe, why this Digeftion ? why this Secretion? why (6 many Strainers, Receivers, Duds, and Valves? and why is fome Food more produdive of thefe Princi- * * 2 ciples C 12 ] pies than others ? Or if they are pre-exiftent Germs that are fecrered, are the pre-exiftent Germs of every Species contained in every Bird, Bead, Fifh, or Plant, that iupplies another with nutritive Juice, and becomes its Food ? What a ftrange Gonfufion ? How unlike that beautiful Simplicity, which Na- ture exhibits in all its Productions ? Germs (hut up within Germs, and Nature fwarming with fupernu* mcrary Entities, all which we readily conceive might have been ftruck out at once, when the Univerfe was created j yet pretend not to be able to underftand how they may be continually formed in Times fucceilive, and as Occasions may require. § 13. This mould feem as unnatural, and as unphi- lofophical, as it is difagreeable to Obfervation : For if every mix'd Body is made up by the Combination of certain Principles, I think we cannot queftion ; but that God may have eftablifhed Forces in Nature, iubfifting Forces, by which fuch Principles may, in certain Circumftances, be invariably united, without any Danger of deviating, fo as to render Generation equivocal j and if every Production in Queftion is a mix'd Body, as it certainly is, we know at the fame time, that, how various foever they are, a fmall Number of Principles differently combined will yield an inconceivable Variety, fuificient to pro- duce them all. Thus may we reduce Nature to what it is really ever found to be, limple in the Beginning of its Courfe, but magnificent beyond Expreflion when diftributed: And this, I believe, will readily be allowed to be its true Procefs in Generation, if, befides taking in all the ordinary 'Phanomena, which no Hypoihefis could yet explain, this [ *3 ] this Proccfs is found confonant to many particular Experiments, fomc of which feem to me to render the Syftem incontcftablc. § 14. Modern Naturalifts have unanimouQy agreed ro lay down, for a certain Truth, that every Plant proceeds from its fpecific Seed, every Ani- mal from an Egg, or fomerhing analogous, pre- exiftent in a Parent of the fame kind. If it is ever of Ufe to feparate difagrceing Ideas; and previously to explain equivocal Words, it is particularly requi- site in this Cafe to determine what we mean by Seeds and Eggs. Seeds and Eggs, in the common Acceptation of thofe Terms, are certain mix'd Bodies, of feveral Dirnenfiom, that immediately furnifh thefe Productions. In this Senfe they are underftood to contain not only the pre-exiftenr Germ, but the Nidus alfo, if I may fo term it, fitted for its Re- ception, and a due Supply of alimentary Principles to be affimilated in proper Circumftances. They are therefore thus far heterogeneous Bodies, that coalefce in a known Time; and their Principles are fo far from being originally united at the Creation, that they fenfibly come together from very diftant Places in all hermaphrodite Plants, and from, different Individuals in all thofe Species, where the Male and Female are diitinct. Now I can- not perfuade myfelf, but that either I have not underftood what has been written on this Subject, or that Authors have not fufftciently reflected upon this, when they aiTert, that, becaufe the ^lantula is found in the Seed, an Oak, for inftance, in an Acorn, that therefore this diminutive Tree bears likewife its Acorns, and thus on through a long Series. [ '4 3 Series, I mall not ask how this fmall Plant can have Seed 5 in the common Acceptation of that Term, it is plain it cannot : and if it has not, where the pre-exiftent Germ is lodged ; how, from an Atom, at fo immenfe a Remove, can it be increas'd to a feniible Mafs, and be fucceffively developed through fo many Generations, till its Time of Appearance? with many other Confequences that may be drawn from hence againft the Reality of pre-exiftent Germs ; all which are too obvious to jrequire a diftinct Enumera- tion. § 1 5. It is in vain for us to pretend to lay down any one certain uniform Rule, and fay to Nature, This is thy Scheme ; fuch arc thy Statutes -y and from thefe thou fhalt not deviate. If in many Productions fhe fixes it as an inviolable Law, that no Individual of that Species fhall appear without a Co-operation of two Parents a Male and a Female, fhe has at the fame time her Hermaphrodites both in Plants and Animals i and if in thefe Hermaphrodites the two Sexes are yet fo diftinc~t, that fhe feems but to have a little diverfified her Operations, without any fenfible Deviation from her primitive Law, fhe will, in an- other Inftance, that of the Titcerons obferv'd by Mr. Bonnet, ad either with or without the Co- operation of a Male. If again you fay that a Female may be impregnated, fo that the Impregnation fhall diffufe itfelf, and penetrate as far as five or fix Ge- nerations, (he will point out to you in the Clafs of Polypes many Kinds, where Generation is carried on without either Male or Female, Egg or Seed 5 tho', among thefe, there are fome of the plumed Sort, where a whole Famiiy3 when by real Ve- getation [i5] getation branch'd out as far as Nature defigns, jointly concurs to give one Egg, or fomethin^ analogous to an Egg, as the Source of a future Progeny. And thus is this Clafs united to its next moft immediate Superior. If you mould (till infift, that the vital ef- fential Stamina of every Plant and Animal were really concreated with the Univerfe, and are now diffufed in Water, Earth, or Air, from whence each will be united to its proper Subject in due time; or that the Experiments of Niewentyt, and other Naturalifts, of the Stems and Roots of Beans, or other Seeds, al- tering their Directions feveral times whendifplac'd, to recover each its own, the Root downwards, and Stem upwards •, that thefe I fay evidently prove vital, efTential, unchangeable Stamina j as they muft be, if original, and concreated with the Univerfe : In- ftances might be brought from the Memoirs of the Royal Academy of Sciences at Tar is, of Trees that have been fo inverted, and indued to change their Direction, that the Branches have become Roots, and the Roots Branches -, a Thanomenon totally incon- fiftent with vital, efTential, and unalterable Stamina* In fine, if at laft you refolve to ftand by this one Refource, that at leaft every Individual proceeds from a Parent like itfelfj that the original Germs, tho" not wholly unchangeable, are yet fufficiently nYd to determine every Species, and that they are either lodg'd in thefe Parents, or fecreted from the Elements by Strainers through their Bodies: I be- lieve I can furnifh, from my laft Summer's Obfer- vations, a Cloud of Inftances, of a new Clafs of Be- ings, whofe Origin has hitherto been unknown, wherein Animals grow upon, are produced by, and, in the [ 03 the Arid Senfe of the Word, brought forth from Plants; then "by a ftrange Viciflitude again become Plants of another Kind, thefe again Animals of an- other, and thus on for a Series, further than the utmofl: Power of GlalTes can carry the mod inqui- iitive Obferver. § 16. It has generally been thought by Natu- ralifts, that microfcopical Animalcules were gene- rated from Eggs tranfported through the Air, or de- pofued by a Parent Fly, invifible to the naked Eye, or even that aiMed with Microfcopes. Yet is it ikange that no Naturalift mould yet have feen them, if they are really fo numerous, when their fuppofed Progeny is lb various, and thcmfelves muft be thought to be fo frequently gliding over the Surface of allftagnant Waters. By what extraordinary Turn is it brought about, might a Naturalift obferve, that fuch furprifing Revolutions fhould happen in thefe little Oceans, as a total Dilappearance of one Species fol- lowed by the almoft immediate SuccelTion of another -, and that in a manner fo fudden and un- expected, that I know not whh-her they are retired, or what new Forms they may have aifumed. If they die, does a whole Race penfh together, without any known Caufe? Or if they have taken any new Form, how is it that I fee none of them altering, juft alter'd, or expanding their little Wings upon thefe Waters, wherein 1 lately faw fo many Millions in an aquatic State ? If it is poffible for them to become flying Infecls in a manner totally invifible, why do not thefe new Parents again de- pofit their Spawn in the fame Waters, and give ,a Succeflion of the late Species, that has difap- pear'd ? [ '7 ] peared ? The Element is not unfit for a new Progeny, fince other Kinds fucceed in it; nay I can trans- port from neighbouring Infufions fome of the fame fpecific Animalcules into thefe abandon'd Infufions, and they will live. Nor yet has the Generation of this Species any peculiar Seafon which confines it : A frefh Infufion of the fame animal or vegetable Sub- dance I apply'd before, will give me again in a little time the very Kind I am enquiring after, and that as often as I think proper to add new Matter. Thus might any Naturalift have reafon'd, who had ob- ferved thefe Animalcules with fome Attention ; and been gradually conducted to doubt of their fuppofed Origin from flying Infects, or Eggs tranfported by the Winds. §17. But there is yet a feverer Difficulty, that fprings from the Confideration of Pafte-Eels : Thefe Animals, Mr. James Sherwood and I, by perform- ing a kind of cefarean Operation upon them, had the Pleafure to obferve were viviparous; and the Royal Society, about the latter End of 1745, or Beginning of 1746, did us the Honour to give At- tention to the Difcovery, when Mr. Sherwood's Paper * was read, and the Experiments exhibited at one of its Meetings. I need not repeat what was at that time or has been fince obferved, where the Multiplication from one Eel once rofe to io<5. It is fufficient to obferve, that thefe Animalcules muftthence confequently be thought to have ar- rived at their ultimate State of Perfection -, no longer liable to change, or to live in any other State 3 too weighty, even the lead of them, to be buoy'd up by or tranfported * See Phil. Tranf. N°. 478, p. 67. ** * '[ ««] tranfported through the Air, and too much of the aquatic kind to fubfift out of Water, or to travel over dry Land, as I have often experienced, and any Gentleman may, by permitting the Water to eva- porate. The Quefrion therefore is, how, in a Mafs from the clearer! Spring-water, and the pureft Wheat- Flour, heated as intenfely as the Composition will admit, thefe Animalcules may be generated ? It is not but that I think myfelf fufficiently enabled, by my Experiments and Obfervations, to anfwer all thefe Queftions, and perhaps many more of greater Importance 5 but 1 have the ftrong Prejudice of near two learned Centuries, and the Opinions of Men of much more extenfive Knowledge and Parts than myfelf, to ftem and get over, before I can eftablifh my own Sentiments upon this Subject -y and therefore am willing to hope I mall not appear to have chofen a tedious and unneceflary Circuit, in tracing out the feveral Steps I have taken, to place my Conduct in a more rational Light. I mud further obferve, that I am obliged, previously to any of thefe Thoughts or Difcoveries, to my Friend Mr. Hill, who translated and commented upon Theophraflus with fo much Applaufe, for two Obfervations, made while I was at London, upon a Seed-Infufion he gave me, and the Semen of a Dog in his own Houfe, which I, and fome other Friends of the Society, faw -, a Peculiarity Angular enough was, that the Animalcules feem'd all hampered, and in ibme meafure adhering by their fuppofed Tails, Struggling as it were with a kind of ofcillatory Mo- tion to difengage themfelves, and not advancing at all progreflively. The Confequence of this Obfer- vation, which fufficiently hinted that they were then enafcent, [ «9 ] enafcent, and that their Tails were no Members given them by Nature to fteer or fwim withal, yet then efcaped our Notice ; and was not plainly clcar'd up, till other fimilar and more diftind Obfervations upon this Clafs of Animalcules occurred fome confiderable Time after. § 1 8. It is now Time to obferve how much I am obliged to Mr. de Buffbns Penetration, who firft en- gaged me in this Enquiry, by his ingenious Syftem, which he was pleas'd to read to me, and at the fame time expreffed hisDefire I fhould purfue it, before I had myfelf any Thoughts of it, or any one Experiment had been try'd. He had been long diffatisfy'd with the Opinion of pre-exiftent Germs in Nature -, and he and Mr. Maupertuis, Prefident of the Academy of Sciences at Berlin, had often difcours'd together upon the Subject. We have feveral Hints of this Dil- fatisfaclion, in a little Book, publifhed by Mr. Mau- pertnis himfelf upon thisQueftion at T'aris, before my Arrival there ; in fhort, it was by general Reflections, and fome other confequent Thoughts, that Mr. de Buffon was conducted to frame his Syftem of or- ganical Parts. Thefe he fuppofed, by Coalition, to conftitute the prima Stamina of all animal and ve- getable Bodies, fimple, uniform, common to all, and confequently to be found in a certain Quantity in every Portion of Food, Aliment, or nutritive Juice ; and from thence to be digefted, and when the Sub- ject became adult, fecreted^ and ftrain'd, for the For- mation of the Seed of every Plant and Animal,- and in this Fluid or Subftance to be confequently found in much Abundance. He further fuppofed thefe or- ganical Parts to be moving when diiengaged, living in Appearance, and gifted with certain Organs, but *** 2 extremely [ ^o] extremely fimple in their Compofition ; being per- haps little more than elaftic Springs more or lefs com- prefs'd, more or lefs diversify Jd in the Dire&ion of their Force. He thought the Calamary Machines I obferved fome time ago to be ftrong Proofs of his Opinion 5 and the fpermatic Animalcules to be Ma- chines, or organical Parts like thefe. § 1 p. For my own part, I was then, as I had been before, fo far of his Opinion, as to think there were compound Bodies in Nature, not riiing above the Condition of Machines, which yet might leem to be alive, and fpontaneous in their Motions ; fuch as the calamary Machines would certainly appear, if they were render'd fo diminutive as to conceal their Me- chanifm, and fuch I then fufpe&ed the fpermatic Animals to be: for Motion in general was but an equivocal Argument, and did not neceflarily imply Life in the common Acceptation of that Term. When, for a further Proof, I inftanced Mr. Hill's Seed-Infufion, wherein many Bodies were feen to move in a manner very different from Atoms in a fermenting Liquid, and yet not fo feemingly fpon- taneous as microfcopical Animalcules, he added, that in his Syftem it muft be fo ; that thefe were detached organical Parts, and that the Seeds, and particularly the Germs of Seeds in Plants, muft ne- ceflarily abound with them more than any other Sub- fiances. Thus did our Enquiry commence upon Sccd- Infufions, from a Defire Mr. de Buffon had to find out the organical Parts, and I, if poflible, to difco- ver which among thefe moving Bodies were ftrictly to be look'd upon as Animals, and which to be ac- counted mere Machines. In the Courfe of this Paper c 2. ] Paper I fhall be as exad as poffible, in philofo- phical Juftice. Whatever Experiments or Difcove- ries are to be afcribed to Mr. de Buffon, were the Refult of his Directions, or jointly made with him, I mall fo fpecify, that they may appear diftinguinYd from all thole others I made at home. The fourfirft Infufions, among them one of Almond-Germs care- fully pick'd out from between the two Lobes and Kernel, I mixed up at my own Lodgings, and then clos'd them in Phials with Corks. The Obfervations that occurr'd, were, firft, a Separation or Digeftion of the Parts of thefe Subftances, and a continual flying off of the mod volatile. Thefe offufcated my GlaiTes at every Inftant, and, according to the Mixtures, yielded a fetid or an agreeable Odour ; particularly that of the Almond-Germs, one ftrongly fpirituous. Eight Days after they had been infus'd, I began to perceive a languid Motion in fome of the Seed-Par- ticles, that before feemed dead; fuch as gave me Encouragement to profecute my Enquiry. It was viftble, that the Motion, tho' it had then no one Characleriftic of Spontaneity, yet fprung from an Effort of fomething teeming as it were within the Particle, and not from any Fermentation in the Liquid, or other extraneous Caufe. A diftinct Atom would often detach itfelf from others of the fame or lefs Dimenfions; and whilft thefe others remained abfolutely unmov'd, advance pro- greffively for the Space of eight or ten of its own Diameters, or move in a little Orbit, then fall off languid, reft between two others, and detach it- felf again and again, with a Continuation of the the fame Phenomena. The Confequences of thefe were obvious, the Motion was not fpontaneousj for [ 22] for thefe Atoms avoided no Obftacle, nor had any other Charaderiftic of Spontaneity. It was not from any Commotion in the Fluid, Fermentation or the flying off of volatile Parts ; becaufe a large Atom would frequently move and detach itfelf from a much lefs abfolutely quiefcent : They did not feem to be enafcent Embryo Animals, from a Depofition of any extraneous Spawn 3 for the Phials had been clofed with Corks 5 nay they were the very Seed, or the Almond- Germ Particles themfelves. § 20. Thefe fame Obfervations Mr. de Buffon made himfelf ; for we examin'd thefe Infufions to- gether a fecond time at his own Houfe; and then it was that he order'd fifteen Seed-Infufions to be made up, which we continued regularly to examine twice a Week, till I propofed to him to take them home, and follow them more clofely by a daily or hourly Infpedion, if necelTary. The Remit of our flrft Obfervations was, that tho* the Phials had been clofe ftopp'd, and all Communication with the ex- terior Air prevented, yet, in about fifteen Days Time, the Infufions fwarm'd with Clouds of moving Atoms, fo fmall, and fo prodigioufly adive ; that tho' we made ufe of a Magnifier of not much above half a Line focal Diffance, yet I am perfuaded no- thing but their vaft Multitude rendered them vifible. It feenVd therefore as if the firft teeming languid Particles we had obferved, vaft in their Dimenfions, if compared with thofe we now faw, had broke and divided into this immenfe Multitude of micro- fcopical adive Atoms. Then it was that we began to lay down a Diftindion between animated and mere organiz'd Bodies; which, tho' far from being at C 23] at this time groundkfs, yet afterwards proved to be falfe. Thefe, and the fpermatic Animals, we fup- poied ro be of the latrcr kind 5 and to be produe'd in their refpe&jve Fluids, by a Coalition of active Principles, much as I had feen the Calamary Ma- chines form'd by Hundreds, tho* abfolutely detach'd, and fwimming at Liberty in the Milt of the Fifh : whilft we thought on the contrary, that the ordinary microfcopical Animalcules, with ftrong Characteristics of fpontaneous Motion and Animation, were to be clafs'd among Animals, and imagined them to proceed from Parent Individuals of their own Species. It was not till fome time after this, that, determined to con- vince myfelf and others, without any Poflibility of Doubt, whether thefe moving Atoms were really pro- duced from without, or from the very Subftance infus'd: I difcover'd all the common microfcopical Animalcules, the fpermatic ones not excepted, were to be rang'd in the fame Clafs, and that their Ge- neration was very different from that of all other animated Beings. J 21. For my Purpofe therefore, I took a Quan- tity of Mutton- Gravy hot from the Fire, and fhut it up in a Phial, clos'd up with a Cork fo well mafticated, that my Precautions amounted to as much as if I had fealed my Phial hermetically. I thus effectually excluded the exterior Air, that it might not be faid my moving Bodies drew their Origin from Infects, or Eggs floating in the Atmo- fphere. I would not inftil any Water, left, without giving it as intenfe a Degree of Heat, it might be thought thefe Productions were convey 'd through that Element. Seeds or Plants were for this Rea- fon [ 24 ] fon improper, becaufe they might have been judg'd to have been previoMy adhering to thefe Plants or Seeds : I neglecled no Precaution, even as far as to heat violently in hot Allies the Body of the Phial j that if any thing exifted, even in that little Por- tion of Air which filled up the Neck, it might be deftroy'd, and lofe its productive Faculty. Nothing therefore could anfwer my Purpofe of excluding every Objection, better than hot roaft-Meat Gravy iecur'd in this manner, and expofed for fome Days to the Summer-Heat : and as I was determined not to open it, till I might reafonably conclude, whether, by its own Principles, it was productive of any thing, I allowed fufficient Time for that Purpofe to this pure unmix'd QuintefTence, if I may fo call it, of an animal Body. From this time I take Corruption intirely in a philofophical Senfe, for the rifing of a dead Subftance, by a new kind of Vegetation, into Life : and no Axiom, how much foever it may- have been exploded, is more true than that of the Antients, Corruptio unius eft Generatio alterhis ; though they drew it from falfe Principles, and fo eftablifhed it as to render Generation equivo- cal, and never penetrated fufficlently into Nature by Microfcopes, to difcover this Clafs of Beings, that are neither generated nor generate in the common Way, yet furnim a Key to lead to the Generation of all others. My Phial fwarm'd with Life, and microfcopical Animals of moll: Dimen- iions, from fome of the largeft I had ever feen, to fome of the leaft. The very firft Drop I ufed, upon opening it, yielded me Multitudes perfectly form'd, animated, and fpontaneous in all their Motions : And thus was I obliged to abandon not only the Notion [ 25 1 Notion preconceiv'd of a Diftin&ion to be made in this Oafs of Animals, between thofe that appeared under a fenfible Angle in the Microfcope, and the atomical ones; but even that Hypothecs alio which I had advanced as probable, in the little Eflay I pub- lifhed in 1745, that fpermatic Animals were no more than Multitudes of fuch Machines as thofe of the Ca- lamary ; for now it was plain of what kind they were, and whence they deriv'd their Origin. § 22. I mall not at this prefent time trouble you with a Detail of Obfervarions upon three or four Scores of different lnfufions of animal and vegetable Subftances, pofterior to thefe upon Mut- ton-Gravy 5 all which conftantly gave me the fame Phenomena with little Variation, and were uniform in their general Refult: Thefe may better appear at Length upon fome other Occafion ; let it fuffice for the prefent to take notice, that the Phials, clos'd or not closed, the Water previoufly boil'd or not boil'd, the lnfufions permitted to teem, and then plac'd upon hot Allies to deftroy their Productions, or proceeding in their Vegetation without Inter- miffion, appear'd to be fo nearly the fame, that, af- ter a little time, I neglected every Precaution of this kind, as plainly unneceffary. I take no notice yet of their Manner of being generated and gene- rating ; in relating thefe Difcoveries, as I believe I fhall be more intelligible, if I follow the Order of Time : It is a Juftice moreover I owe both to Mr. de Buffon and myfelf j for fome were made by him alone, fome by me, and fome of them in Concert together : His Syftern, the Detail of his Syftem, his Experiments, my own Difcoveries, my Thoughts * * * * in [ 26] in confequence of thefe Difcoveriess all thcfe were reciprocally communicated} we made a Secret of nothing to each other. Thus where one Truth feems to lead to, or is the natural Confequence of an- other, it will be eafy, from the Order I have ob- ferv'd, to fee how much I have been cbliged to his Penetration and Foreiight. But this will yet appear more diftinctly, when our fevcral Effays upon this Subject fhall appear 5 and in the fecond Volume of his Natural Hiftory, which will very foon be publifhed, I muft declare for a Fact, that all which precedes his Accounts of the Experiments, begun March 16. N.S. of this prefent Year 1748, was previous either to his own Experiments or mine, and was read to me by himfelf. § 23. In this Order of Time therefore Mr. de Buffon not only repeated the Experiment I have taken notice of, and added particular Obfervations of his own, but made fome intirely new in every refpecl:, peculiar to himfelf. Among thefe, that ne- ver to be forgotten by Naturalifts, which at once deftroys the Opinion of Eggs in viviparous Animals, and fhews the real Ufe of thofe reddifh glandulous Bodies obferved by Vallifnieri upon the Tefticles or Ovaries, as hitherto call'd, of Cows. Every Anatomift knows, that the whitifh Specks, near each of which a Hydatide is plac'd upon all Female Ovaries, were hitherto either look'd upon to con- tain the real Female Eggs, or to be the remaining Scars of Eggs fecundated and diilodgM Vallifnieri, nearer the Truth, thought the large reddifti glandu- lous Bodies, which he calls Cherries, and found upon the Ovaries of Cows, and other Females, in the Time of their Heat, if the Animal is confined to [27] to any particular Seafon, or at any Time, in thofe Females which are unconfined in this particular, were the real productive Organs contributory alone to Generation j yet ftill with a View to the antient Opinion of Eggs, for he fuppofed thefe glandulous Excrefcences to be real oviparous Productions. Mr. de Buffbn, on the contrary, long before Obfervation had realized his Conjectures, rightly thought thefe to no more than temporary Bloffoms, if I may fo term them, not containing in their Cavity, which they have diftinct when they are ripe, an Egg, but the real Female Seed ; that the whitim Specks, fcatter'd upon the Surface of Female Ovaries, were partly the remaining Scars of fome of thefe temporary Blof- foms now faded, as having performed their deftin'd Office, or Embryo - Bloffoms not yet expanded 5 that the Hydatid annexed to each of thefe contained a Quantity of imperfect indigefted Seed; and that, if we took the Bloffom in time, when it mould be intirely ripe for Action, as when a Female is in Heat, or not barren, thefe red glandulous Excrefcences would furnifh a Fluid as really productive of true fpermatic Animals, or organical Parts, as he calls them, as that of any Male obferv'd by Hartfieker% Lewenhoeck, or any other. The Refult of thefe Con- jectures was, that, ordering a Bitch in Heat to be ftrangled, and diflected immediately, we found two of thefe red Excrefcences florid and ripe, one up- on each Ovary, thefe, from their refpective Cavi- ties that ran obliquely under thefe Productions for near an Inch in Length, furnim'd a Tea-fpoonful of a thick turbid Fluid j and this Fluid, obferv'd in the Microfcope with the moft powerful Magnifier, * # * * 2 after [28 ] after fome little time exhibited Numbers of fperma- tic Animals, in every refpect like to thofe hitherto ob- ferv'd by other Naturalifts, animated, and moving fpontaneoufly. Thus was Mr. de Bufon'% Conjecture verify 'd in every Particular. £ 24. About this Time, I think fome few Days after, Mr. de Buffon in my Prefence examined fe- veral Sorts of male Semen; and then it was that, for the firft time, we fairly faw the fpermatic Ani- mals enafcent. Thofe Kinds which fatisfy'd us in this particular were extremely vifcid, and contained in a certain Quantity in the Chryftal of a Watch. Thefe Precautions are not unneceflary ;for if a vifcid Kind be not chofen, and that in a good Quantity together, fuch as that of Stags, ire. or any Seed of the leaft exalted Sort, if I may fo term it, as we found fome to be more fo than others ; it will alter in the Atmofphere by an Evaporation of its volatile Parts, which ferve to hold it though but gently together, after which it will liquefy, vegetate, ra- mify into Filaments, and thefe Filaments again break into moving Globules, efpecially if the Weather be hot, before a fmall Portion can be adjufted to the Microfcope : whereby an Obferver may eaiily be impofed upon, and think the fpermatic Ani- mals original and pre-exifient, becaufe he could not difcern that Action which produced them. This Deception takes Place in all Semen of the more exalted Kinds, fuch as particularly the Milt of Fifh, when it is in a State of immediate Impregnation, and many others : For it is to be obferved, that the Semen of Animals is not at all times in an equal State of Exaltation 5 and confequently that fome Sorts, or [ 29 3 or even the fame at different times, will at fome give the fpermatic Animals immediately, - but at others not fo foon, and perhaps not under fome Hours : which is the Reafon why they have often been laid by Naturalifts, and even by Lewenhoeck himfelf, not to have been found upon Iufpc&ion. By this it will appear, that we had tried many Sorts, before we had the good Fortune to meet with one, in that exacl: Degree of Exaltation neceflary to ex- hibit the whole Procefs of this Vegetation,- and fo may others who fhail be defirous of trying thefe Experiments after us : Yet, when- they (hall at laft have obtain'd a proper Subject, one accurate View will be furlicient, and found to give the Key to the whole Secret. §25. When we had feized this favourable Op- portunity, we faw a fmall Portion of male Semen plac'd on the Microfcrofcope, rirft, as it were to develope and liquefy, then moot out into long Fi- laments, ramify on every Side, thefe open and di- vide into moving Globules, and trailing after them fomething like long Tails ; thefe Tails were fo far from being Members given them to fvvim and fleer by, that they evidently caus'd in them an infta- ble ofcillatory Motion; and were in EfTed nothing more than long Filaments of the vifcid feminal Subftance which they necefiarily trail'd after them; they were of various Lengths in various Animals, and they infenfibly, by the continual progreflive Motion of thofe Animals, grew fhorter and fhorter, till lome of them appear'd without any at all, fwim- ming equably in the Fluid. It was then plain how thefe Animals were to be clafs'd ; their Origin was clearly to be deriv'd from Principles contained in this [3°] this Matter, either by an Evolution of organical Parts, as Mr. de Bujfon fuppofed, or by a real Vege- tation, as I thought, of the fame kind with thofe I had before obferv'd in my Infufions; tho' more prompt, becaufe the Matter was more exalted : confequently the fpermatic Animals were of the fame kind as all other microfcopical Animals, their Origin the fame, their Influence nothing more in Generation, nor any otherwife conducting to its Caufe, than as Effects of thofe Principles in the Se- men, which alone are the true and adequate Caufe of it. See Fig. i . Thefe vegetative Powers, which, from the very Beginning of my Obfervations, I had found to refide in all Subftances animal or vegetable, and in every Part of thofe Subftances, as far as the fmalleft mi- crofcopical Point, I had at this time certain Proofs of; tho* not fo plain and incontestable as thofe I procured a few Days before Mr. de Buffon left *Pa- ris for the Country, and which I profecuted after his Departure. Thefe I communicated to him in few Words the Night before he began his Journey, yet he was not at that time acquainted with any fpecial De- tail of the many Singularities that attend thefe latter Vegetations, for I had but juft then made andenter'd upon the Difcovery of them myfelf. I am obliged the more particularly to obferve this, becaufe the many Confequences he has fince drawn, as well as myfelf, and which, without any mutual Communication, hap- pened to tally with and feemingly to flow from the Difcoveries, were not in Fact deduced from a circum- ftantiated Knowlege of thefe new Phenomena, which he had not, but from this one Principle, that there is in} is a real productive Force in Nature ; in which we had both long fince agreed, however we may have differed in explaining that Action : For whether it be by an Evolution and Combination of organical Parrs, as Mr. de Biiffon fuppofes, or by a real vege- tating Force refiding in every microfcopical Point, may be probably far beyond the Power of Micro- fcopes to determine. But as the Principle from which we depart is intirely the fame, it muft necef- arily lead to fimilar Thoughts, and fimilar Confe- quences. § z6. My fitft Proofs therefore were drawn from a clofe Attendance to all the common Infu- fions, particularly that of Wheat pounded in a mar- ble Mortar. It was plain from them all, that after fome time allowed to the Water to call off the Salts and volatile Parts, which evaporated copioufly , the Subftance became fofter, more divided, and more attenuated : To the naked Eye, or to the Touch, it appear'd a gelatinous Matter, but in the Microfcope was feen to confift of innumerable Fila- ments 5 and then it was that the Subftance was in its higheft Point of Exaltation, juft breaking, as I may fay, into Life. Thefe Filaments would fwell from an interior Force fo active, and fo productive, that even before they refolved into, or fried any moving Globules, they were perfect Zoophytes teem- ing with Life, and Self-moving. If any Particle was originally very fmall and fphe- rical, as many among thofe of the pounded Seeds were, it was highly agreeable to obferve its little Star-like Form with Rays diverging on all Sides, and every Ray moving with extreme Vivacity. The Extremities [ 32 ] Extremities likewife of this gelatinous Subftance exhibited the fame Appearances, active beyond Ex- preflion, bringing forth, and parting continually with, moving progreflive Particles of various Forms, fphe- rical, oval, oblong, and cylindrical, which advanced in all Directions fpontaneoufly, and were the true microfcopical Animals fo often obferved by Natu- ralifts. This brings to my Mind a Phamomenon of- ten taken notice of, and feen with Surprize, Parti- cles detach'd by the Rea&ion of the Water from the Extremities of the Fins of MufTels, which yet continue to move progreflively. I think it fuffi- ciently explained by thefe Obfervationsj and that it is more than probable, that MufTels, Polypes, and other Kinds of this Nature, vegetate in a Manner analogous to this gelatinous Matter. See Fig. 2. § 27. In the Infufion of pounded Wheat, the flrft Appearances, after an Exhalation of volatile Parts, as in every other Infufion, were the fecond or third Day Clouds of moving Atoms, which I fup- pofe to have been produced by a prompt Vegetation of the fmalleft and almoft infenfible Parts, and which requir'd not fo long a Time to digeft as the more grofs. Thefe in a Day or two more intirely difap- peared ; all was then quiet, and nothing to be feen, but dead irregularly formed Particles, abfolutely unactive till about fourteen or fifteen Days after. From thefe uniting into one Mafs fprung Filaments, Zoophytes all, and fwelling from a Force lodged within each Fibre. Thefe were in various States, juft as this Force had happened to diverfify them j fome refembled Pearl-Necklaces, and were a kind of microfcopical Coralloids 5 others were uniform throughout C 33 ] throughout their whole Length, except juft the very Extremity, which fwell'd into a Head like a Reed, if the Force had acted equally on all Sides, or like the Head of a Bone at its Joint, if the Matter in its Expanfion had bore to either Side. Thefe Fila- ments were all Zoophytes, fo teeming with Life, that whenever, upon taking a Drop from the Sur- face of this Infufion, I had feparated the Extremity of a Filament fo fhort as not to confift of above four or five Globules Chaplet-wife j they would ad- vance progreflively and in Concert, with a fort of vermicular Motion, for a little Way, then fall off irregularly to one Side, as if not yet fitted for progref- five Motion, languidly turn their Extremities, and then again lie quiet for fome little time. It was my Fortune however, not in this Infufion only, but in many others, to find fome of thefe Chaplet-like Ani- mals much fmaller indeed than thole of the Wheat- Infufion 5 but intirely regular, conftant in their ver- micular Motion, and which were confequently ar- rived to a higher Degree of Maturity and Perfection. I own I cannot but wonder to this Day at what I faw j and tho' I have now feen them fo often, I {till look upon them with new Surprize. Yet have thefe Phenomena ferv'd me to very good purpofe, and clear'd up many Difficulties in my former Obfer- vations. The Origin of Blight in Wheat, Rye, and other Vegetables, was no longer myfterious: An Atmo- fphere charg'd to an extraordinary Degree with Hu- midity, now plainly appear'd fufficient, particularly while the Grains were tender and replete with a milky 5 * Juice [34] juice in a certain Degree of Exaltation, to produce in them this new kind of Vegetation, and to form their interior Subftance into'Filaments, which are in- deed thofe very Eels I obferv'd fome Years ago in blighted Wheat. This agrees perfectly with another Obfervation made by the Gentleman who tranflated my little Eflay into French: Some of this blighted Wheat, two Years after I had gathered it, I had given to Mr. Trembley, and he to this Gentleman. In a Note he has added, he obferves, that thefe Filaments not only recover'd Life and Motion, after they had been fo Jong dry, by macerating them in Water; but many broke, and difcharg'd from within them Globules, which mov'd with extreme Vivacity. The Application of the foregoing Obfervations to this Cafe is eafy and natural ; nor is it now any Wonder, that thefe Filaments, the vegetative Force mil re- •ftding within them, fhould move and refolve into Globules, or that they fhould have fubfifted fo long, full of that kind of Life they are a&uated with, though dry and without Nourifhmentj for now they ceafe to be Eels, as I formerly thought them. Blighted Rye, which is alfo fo full of Filaments of this Nature, that the Grains are fwell'd in their Diameters, and extended to an extraordinary Length by this new kind of Vegetation, exhibited nearly the fame Phenomena when macerated, and is to be clafs'd accordingly. I am told by fome of the Gen- tlemen of the Royal Academy of Sciences here, that in thofe Provinces of France 0 where this blighted Rye abounds, and is made up into Bread; it produces very ftrange Effects in the poor Country People who feed C 35 ] feed upon it, many of which are here found in the Hofpitals afflicted with a very Angular kind of Mor- tification, which caufcs their Limbs to drop off. There are two Sorts of Blight, in one of which the Grain crumbles into a black Powder -, and the other is that which gives thefe moving Filaments or Eels. Mr. Bernard dejujfieu tells me, that one is from a Cor- ruption of the Flour, and the other of the Grain. It may not here be amifs to hazard a few Queries. Do not all Mortifications, and other Maladies in which there appears an extraordinary Exuberance of Matter in any one Part, proceed from a Weaknefs, a Want of Refiftance, and from Principles of Union, which give to this vegetative Force, found to refide in every Point of animal or vegetable Subftances, more Play in one Part than in another ? For If the Refiftance be not equal in all Parts, the exuberant Matter muft break forth, and caufe that Part to de- compofei and if the Habit of Body be extremely lax, the Decompofttion muft continue j and that, in a certain extraordinary Degree, we fhall call a Mortification. To rub a Wound, or any natural Sore, with Salt and Spirits, is found to be falutary, and preventive of Mortifications ; and Salt I know, by Obfervation, will immediately put a Stop to thefe microfcopical Vegetations, and caufe the Ani- mals to fubfide motionlefs to the Bottom: There fore it is probable, that Salts and Spirits are Princi- ples of Union, and productive of a greater Refiftance in the ductile Matter acted upon by this vegetative Force. High Living, rich Wines, &c. are Preferva- tives againlt many contagious epidemical Diftempers : Do not therefore thefe Maladies arife from a laxer 5* 2 Habit [ 36 ] Habit of Body, and a more than ordinary Adion of this fame vegetative Force ? And may not thefe, and many other Phenomena of this kind, be reduc'd to the fame Principles? But this I leave to the Confe- deration of Phyfkians, who are better Judges of the Extent of thefe Obfervations and Principles. The Subftance emitted from the Globules of the Farina facundans of all Flowers, by an Adion I obferved fome Years ago, is alfo a Subftance of this Nature, filamentous, and in a vegetating State : Nothing can refcmble it more than the Fibres of moft kinds of Mould j refolving all, as they do in Water, into others of a much finer Contexture, when the Vegetation, that had been before flopped by the nitrous Salts of the Atmofphere, begins by the Aflift- ance of the Water to ad again : And I know, by Obfervation, that all kind of Mould is formed by a Procefs of the fame Nature as the Growth of thefe microfcopical Plants ; and to be clafs'd confequently with them, and reduc'd to the fame Principles. I cannot finifh this Article without obferving, that nothing can more perfedly than thefe wheaten Filaments, reprefent in Miniature Corals, Coralloids, and other Sea-Plants, which have Jong been obferv'd to be teeming alfo with Life, and have been fuppos'd to be the Work of Animals, as it will appear to any one, that but infpeds the Figure I have annexed, and recolleds my Defcription. Are not therefore all thefe in the fame Oafs, and is not their Origin fimilar? See Fig. 2. § 28. But thefe Inftances from common Infu- fions, of a vegetative Force refiding in every mi- crofcopical Point of animal or vegetable Matter, how {Irons: C 37 ] ftrong foever and iurprizing, were neither (6 wonder- ful or extraordinary as fomc others I obferv'd after Mr. de Bufforis Departure. From the wheaten fila- mentous Zoophytes it was eafy to infer, that they fprung from, and were Produ&ions of, the Mafs of Matter that had iubfided to the Bottom of the Phial. Yet. this I could not obtain a Sight ofj nor was it pollible in this Way to obferve them without fe- parating them from their Roots and from the Mafs, out of which they arofe. The Method the mod: na- tural therefore which occurred to me for the view- ing of thcfe Zoophytes, without difturbing their Vegetation, and for obferving their whole Procefs, from the Origin of the Plants to their laft Degree of Maturity, was to take extreme thin Slices of Cork, and infert, through little Holes which I made, four or five in each Slice, Grains of Wheat or Barley, or any other farinaceous Seed, for thefe all nearly agree in the Phenomena they exhibit, with the Germ either turned upwards, or carefully pick'd out with the Point of a Penknife, to prevent their ufual mooting. Thefe were permitted to fwim upon the Surface of frefh Spring-water, in a Glafs expofed to the Sun, that the whole vegetating Force might be de- termin'd downwards towards the inferior Moiety of each Grain, which alone could in thefe Circurn- flances imbibe and be faturated with Moifture. This anfwer'd my Purpofe intirelyj my Plants grews downwards into the Water like Corals, but appeared not till feveral Days after the Grains had been thus expos'd ; and were at laft fo large and flrong, that I could fee them with my naked Eye, When [ 38 J When they became thus vifible, I cut off with a fmall Pair of Sciffars the vegetating Extremity, and plac'd it in a concave Object-Glafs with Water. The Plants then took a new Direction, follow'd the Expanfe of the Fluid, and continued to vegetate, while I fupplied them with Water, which I did from time to time, covering them after Obfervation with another concave Object Glafs, to prevent the Fluid from evaporating too faft. Thus I had for the Sub- ject of my Obfervations what I may call a microfco- pical Ifland, whofe Plants and Animals foon become fo familiar to me, that I knew every animal Species, and every individual Plant almoft without any Dan- ger of Miftake ; an Exa&nefs fo neceflary, that it would not otherwife have been poflible to follow the Procefs of this Vegetation without Confufion. From this time I laid afide the Ufe of large In- fufions, and provided a certain Number of Watch- Chryftals, or concave Object-Glaffes, for every Por- tion of animal or vegetable Subftance I was to ma- cerate in Water. The Ufe of thefe is plain and eafy 5 many fruitful little Iflands of various Kinds with Labels and Dates affix'd to each may thus be ob- tained, by placing the vegetating Subftances in thefe Glafles; and this is the Method I would recommend to all thofe who (hall be deftrous to repeat or pur- fue my Experiments. I find my Subject grows upon my Hands, and I am unwilling to take up too much of your At- tention: 1 fhall therefore finifh thefe Obfervations by annexing a Figure of my Wheat-Ifland and its Productions, all which will be fufflciently intelli- gible without any more Words 5 and I mail referve a Multitude [39] Multitude of other Obfervations I have by me in my Journals, upon Infufions and other vegetating Iilands for the Eflfay, which I hope to publifh in fome Months, if thefe few Thoughts and Difcoverics fhall meet with Approbation. See Fig. 3. § 29. Yet muft I trefpafs for a few Pages more; I cannot conclude this Letter without laying down fome general Truths, and recalling thefe fcatter'd Re- marks to fome certain Principles. A few Propo- rtions of this kind, together with the probable Confequences, that feem naturally to flow from them, will not only make my Syftem of Generation clear, but alfo take off many Objections, and render thefe very Obfervations better underftood, when they are reduced under certain Heads. It feems plain therefore, that there is a vegetative Force in every microfcopical Point of Matter, and every villble Filament of which the whole animal or vegetable Texture confifts : And probably this Force ex- tends much farther ; for not only in all my Obferva- tions, the whole Subftance, after a certain Separa- tion of Salts and volatile Parts, divided into Filaments, and vegetated into numberlefs Zoophytes, which yielded all the feveral Species of common microfco- pical Animals; but thefe very Animals alfo, after a certain time, fubfided to the Bottom, became mo- tionlefs, refolv'd again into a gelatinous filamentous Subltance, and gave Zoophytes and Animals of a lelfer Species. This is not only true of all the common microfco- pical Animalcules, but of the fpermatic alfo ; which, after lofmg their Motion, and finking to the Bottom, again refolved into Filaments, and again gave leiTer Animals. [4o] Animals. Thus the Procefs went on through all vlfible Degrees, till I could not any longer purfue them with my Glades : And thus evidently the fper- matic are to be claG/d with the common micro- fcopical Animals. Hence it is probable, that every animal or vege- table Subflance advances as faft as it can in its Re- folution to return by a (low Defcent to one com- mon Principle, the Source of all, a kind of uni- verfal Semen ; whence its Atoms may return again, and afcend to a new Life. This common Element therefore, thoJ uniform in its Origin and homoge- neous, branches out into innumerable Species more and more compounded, more and more heteroge- neous, as they depart and are further from this Source of organized Bodies 5 yet may a Particle often be ar- retted, or moulded into other Bodies, long before it attains, which fome perhaps never do, to this ultimate Refolution. Nor is there any Danger upon thefe Sup- poiitions of falling into equivocal Generations be- caufe the fpecific Semen of one Animal can never be moulded into another, and Seeds may differ fpe- cifically from one another by many invifible Prin- ciples totally unknown to us, and unattainable by Experiments 5 for we are very certain that the Power of GlatTes, or Force of any Menftruum we can employ, muft (till leave us at an immenfe Diftance from the ultimate Refolution of Bodies, in which alone they ?gree, and are homogeneous. Ifay therefore the fpecific Seed of one Animal can never give another of a different Species 5 for, to be this Jpecific Seed, it muft have gone through many Changes trom its firft Origin, and have many Singularities peculiar [4i 3 peculiar to itfclf, and acquired fmce it parted from the homogeneous Element, in which all Kinds co- incide. The active vegetative Fore : that refides in it muft be prccife, its Quantity mufl: be exactly propor- tion^ to the Nature, Solidity. Tenacity, Quantity, and Reliftance of the ductile Matter it has to wade through, if I may fo exprefs myfelfj and thefe Com- binations, are very different in different Subjects. Thus much the many Strainers in every animal Body, neceflary to extract this Semen from the Ali- ment we daily digeft, and to prepare it, feem evi- dently to imply. Yet is not this, fufficient as it may appear, to caufe Varieties in the feveral Species of Semen, all that is to be confider'd : Times and Cir- Circumftanccs make Changes in it even during the Term of Geftation. What does not the Foetus then undergo? and who can determine the Differences between Matrix and Matrix \ between the Matter that is allimilatcd into a Foetus in one Subject, and that in another ; between the fixing Principles, the Quantity of Salts, Spirits, &c. in a Parent of one Species, and one of another ; between the more co- pious or more limited Affluences of ailimilating Matter; and between Times, where even fingle ' Minutes, lnftants, &c. may be of the greateft Con- iequence ? I fee the whole indeed, but confu- fedly, yet do I fee the Source of a Variety; which, boundlefs as it were, if permitted to expatiate at full Liberty, is neverthelefs invariably confin'd, by Him who made and rules the Univerfe, to a certain de- terminate Number of Species. Time, Action, Sea- fon, Quantity of Force, Quantity ofRcfiftance, fixing Principles, Affluence of aflimilatcd Matter, Direction, 6 * and [ 42 ] and numberlefs other Variations, are all employ'd for His Purpofes, and modell'd by that Almighty Power which forms and dire&s the Whole. Thus do thefe Principles, however capable of differing Combinations, yet admit only of a limited Variation, and never deviate further than is confid- ent with univocal Generation. Menders, Mules, im- perfect Foetus's, and other Inftances of this kind, are but rare 5 and as they can be afcrib'd to nothing fo properly as to the Obftacles they meet with, or to fome accidental infuperable Refiftance in the Mat- ter of which they are formed, they do at lead ferve to mew that there is in Nature a real productive Force given it at its Creation 5 and that animal or vegetable Productions are not the Confequences of pre-exiftent Germs, plaftic Natures, or of the imme- diate Hand of God himfelf, any more than the molt regular Operations of the Planetary World. § 30. But to proceed in my Confequences from thefe Obfervations, all Naturalifts mutt acknowlege, that the more compounded the organised Bodies are, the lefs Danger there is of equivocal Generation in the Production of them 5 for thus the immediate Principles from which they fpring, and their Cir- cumftances during the Time of Geftation, mud be much more varied than the more fimple Bodies are, and at the fame time be further removed, from that univerfal Element into which they may all ulti- mately be refoived : And even in the lowed Clafs of microfcopical Animals, I can truly fay, that I never yet obferved any others than Productions fpecifically determined; the fame Subftances giving the lame Plants and Animals, and in the fame uniform Or- der f 43 ] dcr and Defcent. Neverthelefs, tho' thus fpecifically determin'd, no one, that obferves their Origin with ' the fame Care as I have done, will be inclined to afcribe it to pre-cxiftent Germs : It is therefore pro- bable, as I juft now advanced, that when we arrive at the loweft we can difcover in this Clafs, we are yet at an immenfe Remove from the univerfal Source; notwithftanding that fome of them are fmall beyond Conception, and no lefs ftmple in their Motions; which argues their Organization as fimple, and feems to imply that there are among them, or not at a very great Diftance from them, fuch as are only mere Machines, without any true Spontaneity. I have myfelf feen a vail: Gradation, and fuch a one as I have yet but an imperfed Notion of, in a Courfe of continual Obfervations made upon Infufions and Macerations of all kinds, from the mod compounded to the mod fimple ; from Animals of the largeft kind to moving Atoms of the leaft ; from Motions as flow to the moft powerful Magnifier, as the Mo- tion of the Minute-Hand of a Watch to Eyes un- arm'd; from free Progreflion in all Directions to merely ofcillatory Balances -, which all feem to come to at laft in the Courfe of their Decompofition, when they are juft upon the Point of difappearing. § 31. Thus thefe Animalcules, if they may be call'd indifferently by that Name, manifeftly conftkute a Clafs apart? and their greatelt Chara&eriftic is," that they neither are generated, fubiift by Nutri- ment, as other Plants and Animals do, or generate in the ordinary Way. This is indeed true, if the whole Clafs is taken in one general View, yet is the Head of it united to the Species of the next im- 6* 2 mediate [ 44 ] mediate Superior. The Bell- Animal, of which I have had many from my infufed Subftances, and vvhofc Growth I have purfued from its firft Origin, is a Spe- cies of microfcopical Polype, generating and feed- ing as other Polypes do, when once itfelf is gene- rated ; tho'its own original Generation is perhaps dif- ferent from that of the others j for I could never ob- tain any of the larger Kinds this Way. I fay this however with fome Referve ; for I will not alTcrt, but that fome decay'd Water-Plants decomposing in par- ticular Circumftances, and their Subftance exuberating, may perhaps, when urged by this vegetative Force, give Polypes of every kind ; nay I very much fufpec-t, that feveral of the lowed Kinds of vifible Animals may, in due Circumftances, which yet perhaps are rare, be recoverable this Way, when the whole Spe- cies has perifhed in particular Places by fome un- common Accident. This I the more readily believe, from the Reafonablenefs of fome Allowances to be made in this refpedt j all which may be permitted, and muft have been forefeen by the Great Cre- ator, without any Danger of Confufion, or an un- limited Generation of new Species never before pro- duced : He who made Nature, and fees through the whole Machine, well knew its utmoft Force, and has confequently forefeen every Circumftance, and limited its Produ&ions accordingly. Nor indeed can there be a ftronger Argument deriv'd from any Syftem of Generation whatfoever, of an Ail-wife Being, All-powerful, and All-good, who gave to Nature its original Force, and now pre- sides over it, than from the Confideration of an exuberating du&ile Matter, a&uated with a vegeta- tive [ 45 ] tive Force, limited, tho' we know not its exact Bounds, in its ipecific Afcent or Defcent, and ex- panding itfelf in Directions as certain and determi- nate, as the Motions of the Planets. § 32. Thefe Thoughts will appear to be lefs ha- zarded, if due Attention is given to the Generation of the Pafte-Eel. The Royal Society knows it to be viviparous 5 confequently perfect in this State, and fuch as may continue to generate in the common Way, as long as it has an Element and Matter proper for its Subfiftence ; yet is its own original Generation, as far as I can learn by Obfervation, as that of all thefe microfcopical Animalcules, from a ductile vegetating Matter, the Produce of Wheat-Flour and Water ; tho' it undergoes more Changes than others, and lives in other Conditions? afcending for fome time before it enters its chryfalidal or Egg-like State, whence it comes forth a perfect Eel. I have added a Figure of a Group of thefe Eel-Chryfalids, but the Detail of their Metamorphofis 1 fhall referve for my little Effay, and not trouble you now with an Account too cir- cumftantiated of every Obfervation I have made upon them : Befides that I am not yet throughly fa- tisfled in the whole Manner and Procefs of their Generation. See Fig. 4. § 33. But now, to obviate every Objection that may remain againft the Exiftence of this vegetative Force, which feems to be the Key to much Know- ledge, and to remove many Errors ; it may be pro- per to add, that, befides ocular Demonftration, which any Naturalift may have, befides the Precautions I took, that no fuppofed Germs might either be con- veyed through the Air or the Water, or remain ad- hering [46 ] hcring to the Subftances infused; I have often, for thefe Purpofes, made ufe not only of hot Broth, im- mediately clofed up in a Phial, but alfo ot pure ani- mal Subftances, fuch as Urine, Blood, o>c. with the fame Succefs; and in theie, I believe, no one will fuppofe that Germs, Eggs, or Spawn, are pre-con- tain'd, if Care is taken to clofe the Phials imme- diately. Nay I have done more; I have, by reafoning confequently to my Principles, been dire&ed to the Choice of many Experiments, all which I conftantly found to anfwer my Expe&ation : I have thought, for inftance, that the more exalted an animal Subftance was, by a certain Degree of Decomposition, the more apt would it be to vegetate in a proper Ma- trix, and form the Part of a larger Animal ; or, if it extravafated, to vegetate inao the leflerj confe- quently, that if I took the milky Juice of germing Seeds, or that thick turbid Matter which forms the Wing of a Butterfly in its chryfalidal State, thefe Matters muft be more exalted than any ordinary Subftances, and therefore give me thefe microfco- pical Productions fo much the fooner : And in facf, 1 never, in thefe Cafes, fail'd of feeing them within the Space of a few Hours, while ordinary Infufions did not give them under feveral Days. Here it will be proper to obferve, that Natu- ralifts have thought the Butterfly's Wing pre-exiftent in the Caterpillar, becaufe they difcover'd the firft Rudiments of it three or four Days before it enter'd the chryfalidal State 5 but it is then precifely that the Caterpillar firft leaves off eating, thoJ before extremely voracious? and that probably upon ac- count count of the Revolution it finds in all its Parts, while its Forces are otherwifc employ'd, and the Collection of vegetating ductile Matter it had ac- quir'd by plentiful Diet, now as plentifully exube- rates to form the Parts of the Butterfly. Thefe Truths I am the better acquainted with, becaufe I have particularly examined all thofe Subftances : You cannot tear off a Portion of the Butterfly's Wing, even while in the Chryfalid, but you will find it in an Embryo-State, and the Matter which extra- vafates upon your Object-Oafs, if mixt with a little Water to preferve its Fluidity, will almoft imme- diately vegetate into thefe microfcopical Productions. This argues an extreme Activity in it 5 from Activity follows Action, and an Effect, which can be no other than the Formation of the Wing it was con- tain'd in. § 34. Without inftancing in many other Exam- ples, where, by reaibning from thefe Principles, I was invariably conducted to certain Confequences, this laft fufficiently leads to the Nature of animal or vegetable Semen. Thefe latter are Subftances of the fame fort, but more exalted, and from thence adapted to a prompter Vegetation. Of this kind alfo, but not fo exalted, was the gelatinous Subftance I obtained by common Infufions. The Exaltation however of Matter does not flop here* the Jower I purfued this new Clafs of Beings . in its Defcent, the lefs was this vegetating Force clogg'd with refitting Matter, the fwifter was the Motion of the Bodies, and the higher the Degree of Exaltation that produced them. This inclines me to believe, that an animal Subftance may be exalted this [48 ] this way into a Poifon, a Venom, or a contagious Vapour. Hence ftagnating Waters are poifonous and detrimental ; and hence perhaps the vipereal Venom, or any other, may derive its Force ; for thefe undoubtedly are all animal Secretions. Hence perhaps alfo arife contagious epidemical Diflempers, from a Leaven thrown into the Blood by Exhala- tions of this kind. I am the more pcrfuaded of the Truth of this, from the Confideration of Dr. Mead's Obfervations upon the Venom of the Viper : And fwift moving Bodies, which fublide and fhoot into Filaments, feem manifeltly to imply all thefe Con- fequences. I had myfelf propos'd latt Summer to try the Effects of fome of my mod exalted Infufions, by inftilling them into the Veins of Animals ; but as yet I have had no Opportunities for thefe Expe- riments. I might add other plaufible Conjectures, that feem to be the natural Confequences of thefe Dif- coveries, relating to the Origin of Afcarides, Tenig, Agaricks, &c. ; nay perhaps I could main- tain them with Arguments that would feem con- vincing to molt Naturahllsj I might even further fuppofe, with fome Probability, that the mufcular Force, which acts againlt the interftitial Air in my Friend Dr. Tarfonss moil: ingenious Syttcm, in one Word, that all the mechanical Forces of the Body, and the Impreflions which afreet the Soul, may be derived from and afcribed to this vegetating active Force when confined : But I am tired with extend- ing my Views fo far, nor do I at prefent fee an End of the Confequences 3 the Subject and Principles ap- pear fo boundlefs. § 35* C 49 3 § 35. I fhall conclude therefore with fumming up my Sy ft em in a tew Words : I fnppofe all Semen of any kind to be an exalted Portion of animal or vegetable Matter, fecrtted from the Aliment of every generating Subject, when it is adult, and no further Demand is made for its Increafe and Growth 5 this I fuppofe to be endued with a proportionable vege- tative Force $ to be various in various Circumftances, and heterogeneous in different Subjects ; but to be uniform in its Productions, when it falls into a pro- per Matrix, where it finds Matter to aflimilate, of a Quality and in a Quantity fufficient to form that fpeciric Being : Whilft in other Circumftances, it will, if it ext avafates, by the fame vegetating Force, yield all the feveral Phenomena I have above taken notice of. And thus, if 1 am not miftaken, 1 have ob- tained what 1 firft intended to make out, that the fpermatic Animals are not the efficient Caufe of Ge- neration, but only a neceffary Confequence of Prin- ciples in the Semen, which Principles are neceffary to Generation. Thus have I connected my Syftem with our Coun- tryman Dr. Harvey's Obfervation of that fine Tiffue, or Web-like Expansion, obferv'd in the Uterus of Does, in the Center of which the Embryo Fatus, inverted with its Amnion and Chorion, was found to be lodg'd : For let the Vegetation begin from the Semen, and continue to aflimilate the affluent Mat- ter from the Matrix wherein it has taken Root, and the Fawn muft come forth like any other fpe- cific Animal or Plant. I mail only obferve, that Lewenhoeck had difco- yer/d this vegetating Power in the Semen, and had, 7 * like [ So] like Mr. de Buffon and me, feen the Filaments from whence the fpermatic Animals fpringj he even calls them Nerves and Arteries ; and in one of his Letters to Mr. Oldenburg fays, that he faw more in one Minute than the moft accurate Anatomift could difcover by Diffe&ion in a Day: But when he afterwards chang'd this Syftcm, falfe as it was, of Nerves and Arteries for another, I believe, as falfe, that of pre-exifting Germs in the fpermatic Animals, he neglected to improve this Obiervation as he might have done 5 nay he afterwards took no farther No- tice of it, but barely to fay that it was to be ne- glected. This Remark I had from Mr. de Buffon. The Difference therefore betwixt Mr. Lewen* hoeck and Dr. Harvey was, that the firft had an Hypothecs to maintain, and the latter nothing in View but to follow Nature, without trufting too much to the firft Phenomena, as I hope I fhall ap- pear to have done in this my Enquiry. I had almoft forgot one Remark that coincides with my Syftem; that although animal and vege- table Subftances by a chymical Analyfis appear to differ, they are neverthelefs found by a natural Cor- ruption to be reducible to the fame Principles. This has been obferved long ago by many Naturalifts. And now I think I have nothing more to add, only that I would be underftood, when I fpeak of a productive Force in Nature, &c to mean only a Force, which, tho' modell'd by the Supream Cre- ator, goes no farther than the mechanical and ma- terial Parts of a Man. I well know that we are com- pofed of two very different Principles; and no one mere philofophical Truth whatsoever prefents itfelf [ 5i 3 itfelf to me with more Evidence or Convittion than the Spirituality of our immortal Soul. All have ever allow'd Man in his Origin to be a kind of Plant or Vegetable before he is animated ; and alL rational Men have detivJd his Animation immediately from the Fountain of Life, the true Source of all fpiritual Subftances. I think I have faid no more; and thus only would be taken and explain'd. The Principle of Life in other Animals I do not examine into, nor do I think it neceiTary 5 if they are truly fpontaneous, as they feem to be, they have certainly fome Principle diftincl: from Matter, which the Great Creator knows when and how to unite. This Expofition, Sir, of my Sentiments, I thought might be neceiTary ; not that I imagined that either you, or any of the Gentlemen of the learned Society in which you jrelide, would think my Principles any way tending to Materialifm, from which no one can be more djftant or averfe than myfelf ; for I well knew that I had nothing to apprehend from Perfons of fo mi^ch Judgment and Difcernment, and who could not but clearly fee, that there is really no Connexion betVeen thofe Principles, rightly ex- plain'd, and the iDo&rine of the Materialifts : But I was willing to| guard againft the Mifapprehenfion of others lefs acquainted with Matters of this fort, and into whofe (lands this Paper might come, and have therefore tjken thefe Precautions. And now, Sify 1 take this Occafion of return- ing my moft huthble Thanks both to yourfelf and to the reft of the Gentlemen of the Royal Society \ for the Honour I have received, in being elected one of its Members, and for which I have not been able t 52 ] able as yet to make my perfonal Acknowledgments. I hope both you and they will accept thefe Thoughts favourably, which are; humbly fubmitted to impar- tial Inquiry by the Author, who is, with the utmbft eem and Refpecl:, SIR, Tour obliged humble Servant, Turbervill Needham, Explanation of the Figures, Fig. 1 . Reprefents the Origin of the fpermatic Ani- mals. Fig. 2. The Wheat-Infufion. Fig. 3. What I have called an Iflaad in the Wheat- Infufion. Fig. 4. A Groupe of the Chryfdids of the Pafte- Eels. Fig. 5. Is a Draught of one of the firft micro- fcopical Plants or Zoophites wiich I difcover'd, wherein A fhews the Figure of the Plant throw- ing out its Animals, and 8 the fame again after the Animals were difcharged, a;ain putting out a new Shoot from the Stem bdow, through the hollow tranfparent Head, to form a new Head,, and produce another Generation, : V"\) ? 3 >-^ VI' V ,J M% \ 'V-Vjl/' J .■ '!s^_V/.^D •* QruJ $y mm?% *Cb k \: h L4» c/^-j $%<>'i£k ^.4. '.Jtfyn.U ycuifi ¥5* r > lis i HI.