VERMES. 



facculi in thefe animals, for we fometimes find the whole 

 body filled with them. 



The fame thing is feeii in the aphrodite, where the fexes 

 are feparate ; in Imall individuals the body is filled with a 

 whitifli milt, while the large ones have it full of fmall ova 

 in all the intervals of the vifcera. If, as it feems probable, 

 there are particular organs for the preparation of thefe fub- 

 ftances, they have not yet been difcovered or defcribed. 

 The fame obfervation may be extended to the genera nereis, 

 ferpula, and other red-blooded worms. 



It is doubtful, whether or no there are diftinft fexes in 

 the inteftinal worms. In the afcaris lumbricoides, the orifice 

 of generation is found in the anterior third of the body : a 

 fmall (hort veffel foon ends in two larger ones, which 

 gradually diminilhing extend to four or five times the length 

 of the body, and are coUefted m irregular bundles, which 

 may be eafily developed. Thefe tubes, which muil be 

 regarded as ovaries, contain a milky fluid, and an infinite 

 number of fmall ova. 



All the echino-dermata feem to be hermaphrodites, and to 

 poflefs the power of fecundating themfelves : their ovaries 

 fill a large part of the body, when they are fwollen in the 

 feafon of laying. They are fometimes feen bathed as it 

 were in a milky liquor, which feems to hold the place of 

 feminal fluid : this may be obferved in the common fliar-fidi, 

 ■where the ovaries form five large branches, one for each 

 divifion of the body: the eggs are round and reddifli. 



The echini, properly fo called, have from five to ten con- 

 fiderable ovaries, reddifh, lying near the furfacc of the fliell, 

 and ending at the circumference of the anus. They form 

 the eatable portion of the echini. 



In the holothurix, a collection of numerous ramified 

 fmall tubes is feen near the mouth, amazingly developed at 

 particular feafons, when they are filled with a reddifli 

 powdery matter, fometimes collefted in globules. Thefe 

 parts feem to be the ovaries ; but we fee alfo, near the 

 anus, numero-.is whitifli filaments, refembhug worms, and 

 each formed of a flender elaftic thread, turned fpirally, and 

 capable of being unfolded. 



The mode of generation in the aftinix has been defcribed 

 by Reaumur: he dates that " in producing its young, the 

 aftinia inverts its body as it does in rejedling the fliells of 

 animals, which it has fwallowed for food. I have obferved 

 that thefe animals are viviparous, and have feen them come 

 out, perfetlly formed, from the body of the mother, as they 

 are reprefented in fig. ij. It is necefiarv that the cavity 

 rtiould be turned infide out, as we have already defcribed 

 in fpcaking of the digeftive procefs : the young ones then 

 come out of a large tranfverfe filTure. Although the parent 

 may contain fometimes more than twelve (and this opening 

 is large enough to allow feveral to pafs at once), they come 

 out one by one, and indifferently at all parts of the fifTure. 

 Thefe little aftinias, before their birth, are placed in the 

 bafis of the parent ; and lodged in folds of the membrane." 

 Reaumur, Acad, des Sciences, 1710, p. 477.. 



The procefs and the organs concerned in it have been 

 defcribed more in detail by Dr. Spix, in the Annales du 

 Mufcum d'Hift. Naturelle, torn. xiii. " The fpace left be- 

 tween the alimentary cavity and the external envelop of 

 the animal is divided, "he fays, " into longitudinal cavities by 

 folds of a membrane which lines it, and 'is analogous to 

 peritoneum. Each longitudinal cavity contains an ovary, 

 and communicates with two or three tentacula. Each 

 ovary is compofed of three or four cylindrical and united 

 tnbcs, joining together at their bafis into a common canal, 

 .iiid becoming flenderer towards the apex in proportion as the 

 fggs become fmalkr, of which each ovary contains about 



fixty. The common tubes of two neighbouring ovari'.s 

 join into one, and this latter again joins the common tube of 

 the two next ovaries. The oviduft thus formed belongs 

 therefore to four ovaries, and terminates in the bottom of 

 the ftomach. This is the only point at which the young can 

 come forth : hence all obfervers have found them in the 

 ftomach, without knowing how they came there. The 

 eggs are round, yellow, and fimilar to grains of fand. The 

 aftinia: are viviparous, according to the obfervations of 

 Reaumur, Elhs, and Dicquemarre, with which my own 

 agree. I have often feen the young come out of the mouth, 

 of a form perfeftly fimilar to that of the mother. An 

 aftinia, which I have in fpirits of wine, contains a great 

 number of eggs marked with an opaque point, and appa- 

 rently containing the embryo animal. I have even an 

 individual about the fize of a hempfeed, which feems to 

 quit its covering with difficulty, and whofe mouth and 

 tentacula are not yet dift:inft." P. 448. pi. 33. 



The multiplication of polypes and zoophytes by buds or 

 flioots is well known : this feems to preclude the exiftencc 

 of a particular organ of generation. Yet the author juft 

 quoted, has defcribed and figured parts which he confiders 

 as generative organs in a fpecies of alcyonium. See his 

 Memoir and plate as above. 



Peculiar Secretions. — The inky Jluid of the fepia- is pro- 

 duced in a membranous bag, exprefsly defl;ined to that 

 office. The fecreting organ is a villous furface, with fine 

 and long proceffes, adhering to one of the fides of the bag. 

 The fecretion is a very thick black fubftance ; but its p.ir- 

 ticles are fo minute, that it admits almoft of infinit; dilution, 

 and a fmall quantity will tinge a vaft volume of water. 

 This matter, when removed and dried, forms the colour 

 named fepia by the painters ; that of the common cuttle-hfli 

 is a black-brown. The o£lopus has it blacker ; and the 

 Indian ink which comes from China is certainly nothing 

 more than the produce of fome lepia of that country, fo 

 that it is ufelefs to attempt imitating it by artificial mix- 

 tures. Chemical analyfis has difcovered in it a very mi- 

 nutely divided carbonaceous matter, mixed with animal 

 gluten. 



The ink-bag of the oftopus is enveloped by the lobes of 

 the liver, which has given rife to the erroneous idea of fomc 

 moderns, that this part is analogous to the gall-bladder, and 

 that the fluid is a biliary fecretion. 



It is ill front of the liver in the calmar, but free, and not 

 inclofcd in its fubftance. In the cuttle-fifli it is much nore 

 deeply placed, before the inteftines and the intermediate 

 heart. 



In all cafes, its excretory dudl terminates near the anus 

 pouring its liquor into the funnel, which is the general 1 • 

 ceptacle for all the excretions. 



The purple matter, fo celebrated among the anciems, is 

 produced by feveral different gafteropoda : poffibly, how- 

 ever, fome ipccies may furnifh it of a more beautiful or 

 durable kind. It tranfudcs in fome of the genus mur. .\ 

 from the edges of the cloak ; fo that it is no doub' , i 

 duced in them as in the aplyfia, of which the organ w !l 

 defcribed. Swammerdam l^ufpetted that the fac, adi 

 to the organs of geiK-ration, and defcribed by the iiiii 'e 

 term of bladder, was the refcrvoir of the purple; In; 'ii.s 

 fufpicion docs not feem well founded. 



In the aplyfia the operculum of the branchia; is .ir,,i!o- 

 gous to the cloak of other univalves, and differs fi.i;ii it 

 only bccaufc the fliell does not entirely fill it. The tJ,^.- js 

 occupied, in all parts to which the fliell docs not exloid, by 

 a fpongy fubflance, of which all the pores are diftended by 

 the purple matter. This is fo thick, that when it is rx- 

 Gz rieffed 



