VERMES. 



Swammerdam and Needham took the burfa of the fpring- 

 ing tubes for the tefticle, from which it is confiderably dif- 

 tant. They have been followed in this error even by modern 

 authors. 



The tubes themfelves are membranous bodies like worms, 

 terminated by a filament thinner than their boJy, fix lines or 

 more in length. While they remain in their vifcous liquid, 

 or if placed in fpirits or oil, they continue at rell ; but if 

 they are put in water, they become agitated, twill about, 

 and throw out at one extremity an opaque matter. By means 

 of a glafs we can fee in their interior an opaque whitiih body, 

 fpiral like a cork-fcrew, terminating behind in a fpongy 

 mafs, and before in a fimilar fmaller one. It feems that 

 this body is elaftic, and retained by the external membrane 

 of the tube ; that water, by foftening and diffolving the ex- 

 tremity of the tube, allows the fpiral or fpongy body to 

 exert its natural elafticity ; and that the twilling of the tube 

 arifes from the effort which the fpiral body thus makes to 

 efcape. However the matters may be explained, the mo- 

 tion certainly is not a vital one, and may be feen in the tubes 

 of a cuttle-fi(h, which has been preferved for years in fpirits 

 of wine, as foon as they are put in water. 



But what purpofe is ferved by thefe tubes ? Are they, 

 like the pollen of plants, capfules containing a feminal aura, 

 and not giving way to allow its efcape, until they are in a 

 proper fituation J They feem to be developed only in the 

 burfa, which contains them, and they are not found at all 

 feafons. Are the ordinary fpermatic animalcules to be con- 

 fidered analogous to thefe tubes, according to the notions 

 of Buffon? 



Female Organs They are more fimple. The ovary oc- 

 cupies a fituation analogous to that of the tefticle, and is in 

 the fame manner enveloped by a membranous capfule, to 

 which it is connefted at one point only by veffels. The 

 capfule is fimple in the oftopus, divided into two by a 

 feptum in the cutt!e-fi(h. 



The ovary has thoufands of ramifications, and refembles 

 the moft complicated and beautiful tree. The ova enlarge 

 unequally : at the end of a certain time we find them 

 large, prefled together, and angular. Two tubes go from 

 the capfule in the oftopus, and the calmar fagittatum of 

 Lamarck. In the former, when empty, they are fmall, and 

 plaited internally. They end at the fides of the anus. At 

 one-third of their length is a knot, which is a gland tra- 

 verfed by the ova, and furnifliing them with their external 

 covering. It is divided, hke an orange, by longitudinal 

 fepta. 



In the calmar fagittatum there are fimilar glands, much 

 larger in proportion, oval, fituated at the very end of the 

 ovidufts, and divided by very numerous, thin, tranfverfe 

 fepta. The oviduft enters at the fide, and contracts con- 

 fiderably before going out. 



The cuttle-filh and common calmar have a fingle oviduft 

 terminated by a gland of the fame kind. The duft of the 

 latter is larger, and makes two convolutions. 



The dufts of the calmar fagittatum end at the inner fide 

 of the branchice : the fingle tube of the cuttle-fifti and com- 

 mon calmar terminates near the left brancliia, in the fame 

 fituation as the penis of the male. 



Thefe three fpecies have alfo three enormous oval glands, 

 divided, like that of the oviduft, by tranfverfe fepta, and 

 opening at the fides of the anus. Their ufe is unknown. 



The eggs of theoftopus and calmar are united by a gela- 

 tinous fubftance into fmall maffes, while thofe of the cuttle- 

 filh are united by a duftile matter into bunches, like thofe 

 of grapes. The uniting medium is probably furnifhed by 

 the glands which terminate the oviduft : perhaps the three 



glands juft mentioned may alfo be concerned in furnifh- 

 ing it. 



Hermaphrodite Gajleropoda They muft be arranged in 



two feftions ; thofe in which the organs of the fwo fexes 

 have a common ilfue, as the fnail ; and thofe in which their 

 iffues are feparate, or even diftant, as the aplyfia. Under 

 the firft are included the fnail, Aug, teftacella, parmacella, 

 doris, tritonia, and many univalves. 



The flug may be defcribed firft, as being the moft fimply 

 organized : it has only the organs common to the whole 

 clafs ; TOz. an ovary, oviduft, tefticle, vas deferens, penis, 

 and bladder with a long neck. 



The ovary is fituated towards the back part of the body, 

 between the lobes of the bver and the inteftines. It forms a 

 very complicated congeries, like a bunch of fmall grapes, of 

 which each grain is an ovum, while the pedicles are tubes 

 uniting together, and ending at laft in the oviduft. The latter 

 forms many zigzags, and adheres fo clofely to the tefticle, 

 that it may eafily be fuppofed to penetrate its fabftaiice, 

 and receive the fecreted fluid ; but this is not the cafe. 

 Having followed the whole length of the tefticle, become 

 obvioufly larger, and even during the feafon of copulation 

 fvvoUen and plaited, the oviduft terminates in the bottom 

 of the common cavity of generation. 



The tefticle is a white oblong gland, very lai-ge, particu- 

 larly at the feafon of propagation. It may be divided into 

 two parts : the pofterior, behind the junftion of the ovi- 

 duft is oval, and fwells moft at the time juft mentioned. The 

 anterior is oblong. Its ftrufture does not fo much confift of 

 filaments, hke that of the cuttle-fifh, as of grains. It pro- 

 duces an excretory canal, which opens at the bottom of the 

 penis. 



The latter is a cylindrical fleftiy bag, poffeffing internally 

 a prominent ridge in its whole length, and opening into the 

 common cavity of the generative organs. It can be everted 

 like the finger of a glove, and be extended by means of its own 

 fibres, and withdrawn to its original pofition by a retraftor 

 mufcle anfing from the back of the animal, and inferted in 

 the point of the bag, near the vas deferens. When this 

 bag is unfolded, and is protruded externally, it forms a 

 projefting penis, the internal ridge being unfolded fo as to 

 make the internal furface fufficiently broad to become ex- 

 ternal. The orifice of the vas deferens is now found on the 

 very point of the penis, having been before at the bottom of 

 the bag. 



The bladder with the long neck, making the third prin- 

 cipal organ, was called by Swammerdam the refervoir of 

 the purple, beheving that the murex formed in an analogous 

 part the celebrated colouring matter of the ancients. Tliis 

 is not the cafe ; though the real ufe of the part in quellion 

 is not known. It fometimes contains, both in the flug and 

 fnail, a concrete reddifti-grey fubftance : at other times 

 merely a liquid. It is found in all gafteropoda, and may 

 pofllbly be concerned in producing a fluid to cover the 

 eggs. 



The common cavity of generation is a flefliy fac, in which 

 the three preceding organs terminate, and which has an ex- 

 ternal opening under the right fuperior horn. 



When fnails copulate, they evert this fac, which then 

 prefents three openings ; wz. of the oviduft, bladder, and 

 penis. The latter quickly comes out of its opening, and 

 enters the oviduft of the other individual. In this way 

 copulation is effefted : the laying takes place fome days 

 after. 



The intimate conneftion between part of the oviduft and 



part of the teftis and vas deferens, deceived Swammerdam 



concerning the nature of thefe organs. He firft conceived 



II the 



