GENERATION. 



tiance of the fixtus to both parents in the human race, in 

 animals and even in plants, may be urged in fupport of the 

 fame doclrine. 



The old opinion, which fuppofes that males arc produced 

 by the right teftis and right ovary, and are contained in the 

 right fide of the uterus, while females are formed on the 

 left, is deftitute of all foundation. A male with one teilis 

 has ])roduccd children of both fexes ; and male or female 

 fcetufes are feen indifferently in the right and left coniua uteri 

 of animals. 



The hypothefis of Hippocrates andAriftotle was adopted 

 by Buffon, and is preftnted in his natural hiftory with all 

 the advantage it can derive from his warm imagination and 

 eloquent diclion. But figurative language rocompenfcs us 

 very imperfecT:ly in fcientitic matters for want of obferva- 

 tion, and hafty generalizations ; and the theory of Buffon is 

 fo dellitute of foundation, tliat we can hardly think it 

 worthy of notice. He conceives that there is a matter in 

 nature, compofed of incorruptible molecules, always living 

 and active, and deilined to the nutrition and evolution of all 

 organized beings. Tliefe particles are received in the food, 

 and are applied to every part of a plant or animal. Every 

 animal is an ii^terior mould, by which thefe particles are 

 fafhioned to their particular fliape. When there is more of 

 this matter than is required for purpofes of nutrition, the 

 overplus is conveyed from all parts of the body to the tefti- 

 cles of each fex, which are its refervoirs. It exifls here in 

 a liquid form, and contains molecules analogous to all parts 

 of the frame, fufficient to form a fmaller being, exaftty 

 fimilar to the large one, from which it is produced. The 

 molecules compoiing the new being are analogous to thofe 

 of all parts of the body, from which tliey have been ron- 

 Teyed to the telles, and may be deemed a kind of extraft 

 of the old body. Tliis matter, having paffed through the 

 interior mould, and finding the uterus in a favourable ftate, 

 generates a neV animal. We (hall not abufe ovir reader's 

 patience by the further detail of fuch vague chimeras ; they 

 more than juft ify the farcafm of Voltaire in his " Homme 

 aux quarante ecus." "Ah! monfieur le favant, fays the man 

 aux quarante ecus, could not you inform me how children 

 are made? no, my friend! replies the favant ; but I will 

 teU you what phiiofophers have imagined on this fubjeft, 

 or, in other words, how children are not made.'' This jeu 

 d'efprit contains a lively ironical account of the various thee- 

 ries of generation, which the reader will find much more 

 entertaining, and quite as inilruftive as the original accounts 

 of thefe reveries. 



Of thofe, who confider tliat the father has the principal 

 ihare in producing tiie child, Leeuwenhoeck is the foremo'.l. 

 He confidcrs the fpermatic vermiciili as men in miniature ; 

 and conceives that one of thefe crawls in fome way or other 

 into the ovarian veficlej and is there developed. 



That the foetus is produced by the mother has been more 

 generally fuppofed ; and feenis more probable »n the firil 

 glance, fince the child moll certainly comesfrom the mother, 

 although it is by no means clear that it ever went to lier from 

 the father. The analogy of almofl all animals, and of plants, 

 favours this opinion. The generation of the aphides has 

 been adduced in its fupport ; where a fingle fecundation fuf- 

 fices for fereral generations. In the frog and toad, and in 

 the bird, it is very clear that the foetus pre-exifts in the ova- 

 rium ; and that t!ie contaft of the femen produces at firil no 

 perceptible change in its appearance. Indeed the wonder- 

 fully Imall portion of fecundating fluid necefiary to produce 

 the requifite effcft in the frog or toad would lead us to con- 



clude tha i cannot excite any very great tliange at the fir/l 

 moments of its apphcation ; and this circumilance, together 

 with the obvious cxillence of the fornethlng, wiiich is after- 

 wards evolved into a tadpole, in the ovarium before copula- 

 tion, clearly proves the pre-exiftence of the germ in the fe- 

 males of this fpecies of animals. " A quantity of feed,'' 

 fays iSpallanzani, " far more inconfiderable tiian we fhould 

 ever Iiave imagined, is fufficient to animate a tadpole. We 

 have feen that it is not neceffary to cover the fatus complete- 

 ly with this prolific fluid : a drop will fuflice. Further, 

 three grains mixed with twelve, and even with eighteen ounces 

 of water, communicate to every part of it the power of 

 fecundation, fince tadpoles placed in any part of the mixture 

 are fecundated. The three grains of feed mull therefore 

 have been dilTufed ti:rough the whole mafs of v.ater. But, 

 what an enormo\is divifion of its particles naiil fuch a dif- 

 fufion occafion ! How fmall a fhare of prolific liquor muft 

 fall to the fhare of each tadpole ! Yet there are facts which 

 prove that the ft-men ilill retains its virtue after this exceffive 

 divifion ; for 1 have found a globule i-jOth of a line in dia- 

 meter, taken out of a mixture of three grains of feed with 

 eighteen ounces of water, was often capable of fecundatino- 

 a tadpole. Defirous of knowing the proportion, which the 

 tadpole (that of a frog is 2-3ds of a line in diameter) bears 

 to the particles of feed diffufed in a drop of this dimenfion, 

 I have found, on calculation, that it is as 1064777777 to i. 

 How infinitely fmall, therefore, is the quantity of feed in 

 comparif'i^n with the bulk of the foetus, which it fecundates ! 

 This deduclion led me to calculate the weight of the parti- 

 cles of femen difperfed in this drop of water : it is 

 7 0-1 (•,'«? i iv of a grain. That I might view thefe particles 

 under every polTible afpeCl, I reduced their bulk to cubic 

 lines, when it appeared to be about equal to -j ttst ■ '■■ sr - 3 

 of a cubic line." Differtations, vol. ii. p. 212. The re- 

 fearclies of Haller, and of others on the formation of the 

 chick, have clearly proved the pre-exillence of the ftctus in the 

 female of birds. 



But, although this hypothefis appears to beftipported by 

 the moft numerous and fatisfadlory proofs, there are difficul- 

 ties oppofed to its adoption. " It is very certain," favs 

 Haller, " that children often refemble the parents in the 

 human race ; fo that you may diilinguiih one brother by his 

 refemblance to anotiicr, or know a fon by his likenefs to tiie 

 father or mother, or even grandfather or grandm.other. All 

 the ii>dividuals of fome families are charatterized by particu- 

 lar hncs oi countenance. My own family iiave now been 

 dirtinguilbed for tallnefs of ftature for three generations, 

 without excepting one out of many grandfcns defcer.dtd 

 from one grandfather. Families of red-haired perfons are 

 not uncommon : the difagreeable colour being derived from 

 the father or moth.er or grandmother. But this refemblance 

 or children to parents is difccrned moil plainly when there 

 is any defeft or peculiar for.mation tranfmitted from one to 

 the other. The tranlmiiTicn of difeafe may perhaps not be 

 deemed fo furpnfing, fince nobody denies that the mafs of 

 fluids is derived from the m.other ; but the father contributes 

 the fmalleil drop poiTible, if any. Yet we find various dif- 

 eafes, or difpofitions to difeafe, pafTing from either parent 

 to the offspring. This is matter of common notoriety with 

 refpeft to gout, rheumatifm, infa:iity, fcrofala, confump- 

 tion, ^&c.but there is more doubt of fome others, as cata- 

 raft, hernia, aneurifm, fquinling, harelip, clubfoot, fa- 

 tuity, &c. of which, liowever, auihors relate many exam- 

 ples. We know a very remarkable inflance of two noble 

 females, who got huibands on account of their wealtli, al- 

 though they were nearly ideots, and from whom this mental 



defeCl 



