A S C 



wV.ile tlic leriffih 



A S C 



volutcd appsrntus is compofcJ of very fine traiifparent 

 ii-ienibra\ic3 ; it is never found tmjity, but always dilUndcd 

 with an opaque fluid, in which arc a number of ova contain- 

 ing youn" worms. Some have confidercd thefe tliread"? 

 (which afways protrnde if the (kin of tlie worm be divided) 

 as yoiuicr worms, and have contended that the afcaris was vivi- 

 parous ; but it is not ; and ova, fimilar to tiiofe found in 

 the Fallopian tubes, will be found in ihe mucus furrounding 

 the worm in the intelUiKS. 



As the afcaris luiwbricoides has long been confounded 



Malomknl D.fcr,p!hn. Cuticle— The covering or cxter- with the lumbricns tenellris or earth-worm it may be pro- 



nal mendjrane of the worm, which may be confidered as per to mer.tion that the lumbncus terrellns has but one ve- 



the cuticle is very ftrong, ekftic, thin, fmooth, and tranf- fide at its head, m the middle of which is its mouth ; it 13 



ing its length and extending itfelf again, 

 cif the afcaris lumSvicoides is never diminiflitd ; the he:id is 

 alway!! f;nt fonvard by the worm curling itf-^lf into circles, 

 and fudJenly extending it with conlidcrablc force to foiiie 

 <li (lance. 



It is faid that the afcaris Inmbiicoidis is not herma- 

 phrodite. The worm here d;fcribed is coHfidered as the 

 female. Dr. Hooper fays lie has examined a very coniide- 

 rable number, a.id' has never mtt with any other appear- 

 ances than thefe. 



Cuticle Tl 



parent,' and cafily' fepanTtos from the parts underneath by flat towards the tail, and is furm^(hed_ with fiiarp briftles on 

 maceration in water ; under this wc find the cutis or true 



its under lurfaco that ferve it for feet, which the animal 

 Ikin, which is con?iderabi7thicker'lhanThe former, and re- can erea or deprefs at pleafure ; its annuls;^ are very large 



tains marks of the mufcles which it covers ; it is alfo very and llrongly marke-_d. and its colour is of a dul^cy red. 



llror,"- elallic and tranfparent. When the cutis is removed. Upon the under furface there is a large femilunar fold in the 



the imifcks, obfervable through the llcin, pvefent themfclves ; H.in, into which the animal can draw its head or tliruft il 



they do not entirely furrouud the worm as they at firft ap- out at will ; in all thefe it is llrongly di(lingui(hed from 



pear but are two' diflintl orders afting in oppofition to the afcaris luinbricoides. This lumbncus has alfo an e!e- 



cach other, for the two longitudinal lines which extend vatcd belt in its middle, the afcaris a depred'ed band ; 



from oil" extrem'^y of the worm to the other, are each of on each fide of the afcaris there is a longitudinal line ; 03 



them compofed of two diilinft tendons, feparablc from one the lumbricns, there are three lines upon Us upper furface. 

 another ; thefe tendons ferve for the attachment of the femi- The afcaris vermicularis, called the maw or thread worm, 



lunar mufcles which cover the worm from the head to the when full grown, is about half an inch in length, and in 



tail. Upon carefully removing the femihmar mufcles from thicknefs refembling a piece of fine thread ; the head, or 



the'head to the deprcfied band, a number of minute veficles obtufe extremity, is divided into three vcficlcs or papillse, 



are to be feen (by means of a glafs) filled with a fubinu- in whofc middle is an aperture, which is the mouth. The 



cons fluid which iffues out uoon punfturing them. This body is about a third of the length of the animal, begin- 



cellular or parenchymatous apparatus clofely embraces ning from the head, and terminating in the tail, and is of 



the intellinal canal from the head to the deprefled band ; a rugofe, pellucid, annular fabric ; the tail commences at the 



but from thence to the tail there is merely a fibrous fmalT aperture or anus, and becomes Icfs and lefs, terminating 



kind of cellular membrane. When the mufcles are re- in a fine point. 



moved from the depreffed band to the tail, an extremely Thefe worms are moftly confined to the re£lum and colon, 



delicate membrane appears, which as a peritoneum embraces and that principally of children ; but they are often found in 



the abdominal vifcera, and lines the cavity of the abdomen, the coecum and fmall intellines, and even tlie ftomath, and 



which cavity extends from the depreffed band to the tail ; frequently get into the vagina, and even uterus, bladder, 



it is didended with a tranfparent fluid, and contains the in- &c. Their number fometlmes exceeds all bounds ; in wWch 



teftinal tube, and an apparatus fuppofed to be fubfervieiU to cafe the excrements, when full evacuated, appear quite 



o-eneration. The intellinal tube or canal begins from the alive from being covered with them ; generally a fmall 



Bioath, and continues nearly half an inch in a parallel form, number are evacuated from the redlum every day, produc- 



which'Dr. Bailie calls ocfophagus ; it then becomes larger ing a moll unpltafant fenfation of itching by their pieicing 



and tranfparent, increafing in fiy.e till it arrives to the begin- the lldn in a degree with their awl-fhapcd tails. Their 



ning of the abcomen, clofely embraced by the parenciiy- conllant aftion is one of their mod ftriking cliarafters, ap- 



matous fubdance ; it now obtains the dimenfions of a crow pearing to be never at reft. On expofure to the air, they 



quill, and pa(fes llraight, ilill enlarging, through the whole have the power of piercing the fxces, and burj-ing them- 



leni{lh of the worm to within an tiglith part of an inch, felves in it alinoll inllantly. From the extreme aftion of 



where it fnddenly becomes narrow, and terminates in an this fpecies, the genus has obtained the name afcarh, for 



anus. This canal is generally filled with a greenilh coloured a^;tapi^!i» fignifies the fame as o-xafi^iiv, yi/Z/a/v, inqu'uie mo- 



fluid of the confillence of mucus. If a portion of this tube 'uere.^ 



be macerated a few days in water, it exhibits diftinft tunica. They are not hermaphrodite : the male docs not exhibit 



the external of which is a portion of the peritoneum ; it is any of the gyrated apparatus ; the ftomach and inteflinal 



externally covered with filaments, which may be veflcls of canal have in appearance a different arrangement from thofe 



nutrition. The fecond vifcus is confidered by fome as pe- in the female : bat the male organs of generation have not 



cuhar to the female, and all agree it is for the purpofe of been deteded, probably they are too minute. The female 



generation ; it begins about the middle of the worm, where has upon its exteri al furace, about the eighth of an inch 



the cavity of the abdomen coaimences by a (lender tube from the head, a fmall pundiform aperture through which 



which is continued from the punftiform aperture fituated in the young are protruded, and when highly tnagnified, its 



the depreffed band between the two longitudinal lines. This internal cavity appears filled with the convoluted apparatus ; 



lube which is termed the vagina, foon becomes larger, and Dr. Hooper fays he has feen upwards of one hundred 



when it commences uterus, and divaricates into two large young ones efcape through this aperture all alive, and 



crura which for the fpace of four or five inches are of an very vivacious feveral hours after the death of the mother ; 



uniform diameter, then fuddcnly diminilh and appear like upon a little prcfTure being made upon it. 

 opauiie tiueads, embracing in every direftion the intellinal _ Anatomical Ohfervations . The integuments of this fpe- 

 liibe Werner confiders thefe as Fallopian tubes. This con- cits are fimilar to thofe of the lumbricoid afcaris, and con- 



