GENERATION. 



tis it approaches the body. Water or other fluids rendered 

 them iiiiiijediately motions. They may be fometimcs ob- 

 ferved, in the clots of the femen, before they have difTolved, 

 attached by their appendages to the filamentous matter : 

 they llriiggle to difengage themfclves, and then fsvim about 

 in the fluid. The motion continues much longer when the 

 temperature of the atmofphere is increafed : at 36 ' all mo- 

 tion had ceafed in three quarters of an hour : at •49'^ in two 

 hours; at 59 in three hours and a half : and at 81 ' tlif'y 

 lived for feven or eight hours. The corpufcula were feen in 

 the fluid obtained from the epididymis and tcfticles of various 

 living and recently dead animals. That they are not formed, 

 according to the fentiment of Buff'on, from the filamentous 

 part of the feraen, is proved by this ; that they are moll 

 abundant in the fluid part, and even do not exift at all in the 

 clots, where they are examiiied in a very recent (late, and 

 freed as much as poflible from the thinner part of the femi- 

 nal fluid ; while the latter, at the fame time, abounds with 

 them. Nor are they generated, as Needham aiferted, by 

 expofure to air. For Spallanzani faw them in the ufual 

 numbers, when the time employed in taking the fluid matter 

 from the feminal veffels fl.ill warm, to prefent it to the mi- 

 crofcope, did not exceed a fecond ; and they were ob- 

 ferved in the fame numbers in feminal fluid carried without 

 delay from the epididymis of a living ram to the microfcope. 



Great care and attention arc neceflary in obferving the 

 appendages of thefe vcrmicuii, and hence they efcaped the 

 notice of BuiTon. It is wonderfully flendir, and at the 

 fame time tranfpai-ent, fo that too flrong a light confounds 

 it with the fcminal fluid : the Aider Ihould be fine and thin, 

 and the drop of fluid very thin : and a microfcope of a Angle 

 lens is preferable to the compound one. 



They live longer in clofe veflels, than when the fcmen is 

 expoled to the air : and they alfo live longer in vacuo. The 

 difference of time at which they die in thefe different fitua- 

 tions amounts even to one, two, or three hours. " Thefe 

 fails prove that the air is noxious to the vermicuh, and the 

 following prove that it is the caufe of their being in conti- 

 nual agitation. With the blovv-pipe I formed capillary tubes, 

 one end of which I immeried in recent femen ; it afccnded 

 the cavity, filling the tube to a certain height. Breaking 

 the tubes near the part to which it afcended, I prefented 

 this extremity to the blow-pipe, and iinmediately fealcd it 

 hermetically. I did the fame to the other end, by which 

 means the feminal fluid was deprived of all communication 

 with the external air. 1 drew out the tubes, fo that tlu- 

 thinnefs of the tubes permitted me to fee the vcrmicuii 

 within. The peculiarities prcfented by the vermicull in the 

 tubes were very different from thofe of the refl. All, or 

 at leaft mofi of them, had a Angular mode of moving. 

 Some had that fort of activity obferved in thofe, which ex- 

 perience the influence of the open air. Others had a con- 

 tinued irregular motion ; they changed from quicknefs to in- 

 aftivity, and reciprocally. Others flopped entirely, and, 

 after reiling fome minutes, relumed their former velocity ; 

 befides, they were not obferved to rim againil the folid por- 

 tions of the femen, but to avoid them by turning afide or 

 retreating. Thefe peculiarities always fucceeded better, and 

 ^^•ith more uniformity, when the tubes were kept warm. I 

 have before faid that the longefl period of life, of the human 

 fpermatic vcrmicuii, was fcven or eiglit hours, wlien cxpofcd 

 to the open air, but this period is greatly prolonged when 

 they are included in tubes. In iumm.er I have fucceeded in 

 preferving them two days or more ; and in ipring and au- 

 tumn they have lived almofl three.'' P. 158, 



Cold, near to that of freezing, renders the vermiculi mo- 

 tionlefs ; but they are recovered by the application of heat. 



Vol. XVI. 



A temperature of 131' kills them ; but the animalcula pio. 

 duccd in the femen by putrefaction are deflroyt-d by a tem- 

 perature of 1 08 . 



To this account of the feminal vermiculi we fubjoin the 

 following refleftions on them by Bonnet, obferving only 

 tint we are in a flate of the moll profound ignorance of all 

 the [Joints alluded to in his queilions. 



«' The vcrmicuii arc, of all the animalciila of liquids, thofe 

 which liave mofl excited my curiofity ; the clem.ent in \\ iiich 

 they live, the place of their abode, their figure, motion, fc- 

 cret properties, all, in a word, fliould intereft us in fo Angular 

 a kind of minute animated beings. How arc they found 

 there, how are they propag-.ited, how are they developed, 

 how are they fed, and what is their motion ? Vv'hat becomes 

 of them when the liquid tliey inhabit is returned by the veffels, 

 and mixed with the blood : Why do they appear only at th>.' 

 age of puberty ; where did they exift before this period ? Do 

 they ferve no purpofe but to people that fluid, where they 

 are fo largely fcattered ? How far are we from being able 

 to anfwer any of thefe queflions!" Spallanzani's Tracl:., 

 p. 179. The reader may alio confult, on this fubjecl, 

 W. F. von Gleichen liber die Saimien-unk infufions-thier- 

 chcn, Norimb. 1778, 4to. 



The opinions of Leeuwenhoeck concerning thefe vermi- 

 culi ; ik's. that they are of different fexcs, that they co- 

 pulate, become impregnated and produce young ; and that 

 they are the rudiments of the future beings, to be conveyed 

 by copulation into the body of the mother, and tliere deve- 

 loped ; are deilitute of all proof, and completely chimeri- 

 cal. 



We have no accurate accounts of the fcnfible properties, 

 nor any chemical hiftory of the fluid feparattd in the tellis. 

 When obferved in the vas deferens or epididymis of man, 

 after death, it poffeffes a light-brown or yellowifh colour, 

 and approaches in fluidity to water. It may be feen in ani- 

 mals, on cutting into the teftis or epididymis, m;;ch thicker, 

 vilcous, and of a grey colour. At leail it has this appear- 

 ance in a dog. The whole gland, in a healthy ariraal, is tur- 

 gid with this fluid. The contents of the vcficulae feminales 

 differ in their appearance from the fecretion of the tefticles. 

 It is a browniih or yellowifli fluid of light colour, femi- 

 tranfparent, and often containing flakes or coagula, fo as to 

 vary in confiftence in different parts of the bag. Expofure 

 to the air produces no change in its confiftence, as it does in 

 the femen. Sometimes the contents of thefe bags are a clear 

 mucous fluid. Mr. Hunter took the trouble of obfers-liio- 

 them, in two healthy perfons killed fuddenly, immediately 

 after death. In one the fluid in the veficulx was of a lighter 

 colour than is ufually found in men who have been dead a con- 

 fiderable time ; but it was not by any means like the femen 

 either in colour or fmell." In the other " the contents of 

 the veficulae were of a lightifh whey colour, hafin-T nothin'^ 

 of the fmell of femen ; and in fo fluid a ftate, as to run out on 

 cutting into them." (Obf. onthe animal Economy, p. 28.) 

 Thus it appears that the fluid of thefe bags differs' both from 

 that contained in the teftis, and from the femen emitted in 

 coition ; confequently, that they are not merely refervcirs for 

 the matters feparated in the teliicle, but that they add to the 

 fecretion of tliat gland fome conilderable bulk of fluid, 

 feparated by their own veflels. The peculiar organization 

 of their internal furface would have led us a priori to ex- 

 pcft this, as it exhibits an arrangement of parts found only 

 where fome fecretion is performed. The fame argument 

 will lead us to alTign a fimilar fuutlion to the enlarged por- 

 tion of the vas deferens lying by the fide of the veficula fcmi- 

 iialis. The exaft nature of the fluid feparated in the velicul.c 



F is 



