r-. 



KNTOXOA. 



67(1 



entire, ha* thrown great obstacles in the way of their investigation. 

 The bead wu for a long while unknown, and it was disputed whether 

 nouruhment wu taken in by the lateral pores of the several jointa 

 or by the mouth alone. Uudulphi says the latter, and it seems now 

 pretty clearly determined that the former are mere outlet* of the 

 generative organs. The length to which the T. ioli*m a capable of 

 attaining it very considerable, but quite indefinite. Those passed 

 Dow-a-days seldom exceed twenty feet, but in former times we read 

 of much more gigantic specimens ; but whatever may be thought of 

 some of the accounts which are quite improbable, it indubitably has 

 occasionally attained a very great length, having been found extending 

 from the pylorus to within a few inches of the anus, and then by no 

 tnnam fully stretched out Such cases are however very rare. 



The determination of the species in this genus is very difficult : 

 they may be divided for greater convenience into three sections : 

 The first are without a proboscis, the Ttrnur inermtt; the second have 

 one, but unarmed, T. rottrllaiir ; the third are furnished with an 

 uncinated probnecis, T. armata. 



3. CaryopliylltTtu hss the body flat, continuous ; the head dilated,- 

 and divided into flattish processes ; it is furnished with an upper and 

 under lip. The species of this genus occur in the intestines of fishes 

 (carp, 4c.). 



4. Scolts. The body is flat and continuous; the head has four 

 (bane on it It occurs also in the intestines and abdomen of fishes, 

 sepue, Ac. 



5. (iymnorkynfhiu. This genus has the body very long, with a 

 globular receptacle at the neck ; head with two opposite fossae, and 

 four naked retractile probosces. The species occur in the muscular 

 substance of many fish. 



6. Tctrarhynchiu. Body flat, continuous, head with four fosses and 

 four retractile probosces, furnished with recurvated spicular processes. 

 It occurs in reptiles, fishes, itolltuea, in the muscles, branching 

 stomach, and its membranes, the liver, and peritoneum. 



T. Liyula. In its first stage of development the body is elongated 

 with a longitudinal fissure, without any appearance of head, or organs 

 of generation. In iU perfect state there is a simple fossa on each 

 side of the head, and the ovaries and processes form a single or double 

 row along the median line. The species occur very frequently in 

 birds and fishes, but very rarely in Mammalia. 



8. Trittnophortu has the body elongated, flat, sub-articulated; 

 mouth bilabiate, and furnished on each .side with two tricuspid 

 acicular processes. It is found in fishes. 



The Trematode order is divided into six genera, which also include 

 only two species infesting the human body. 



1. The first genus is Monotloma, which has only a single anterior 

 pore. It occurs in Mammalia, birds, reptiles, and fishes. 



2. Ami>hutoma is furnished with two pores, one anterior and 

 one posterior. Found in the stomach, intestines, and abdomen, 

 and in the hydatids of the viscera of mammals, birds, and reptiles. 



8. IHtloma. In this genus there are two pores : an anterior and a 

 ventral. An immense number of species are known, occurring in 

 Mammalia, birds, fishes, to. The D. hepaticum,, or Fluke-Worm, 

 frequents the gall-bladder and ducts very frequently in some animals, 

 as the ruminating, and is particularly common in the sheep in the 

 disease called the Rot It has been discovered in the gull bladder of 

 the human subject, though very rarely. It bears a considerable 

 resemblance in its shape to a melon-seed, being flat, and appearing 

 lanceolate at each end, as seen with the naked eye, though, when 

 magnified, the extremities are found to be obtuse, the tail being the 

 broader of the two. The anterior pore, or true mouth, is round and 

 small ; the posterior cavity is imperforate, and only subservient to 

 adhesion and locomotion ; it is situated in the ventral aspect of the 

 body in the anterior half. Between these there is a third orifice, 

 1 to the generative system, and from which a small cylindrical 

 if generally protruded. The Fluke is hermaphrodite and 

 oviparous : it lives upon the bile, which is absorbed by the month, 

 and is at once so digested or modified by the Teasels which go off 

 from thence, as to become immediately fitting nourishment for the 



4. THttvma has three pore*, the anterior simple, and the posterior 

 radiated. It is found In the gills of one or two species of fish. 



5. Pmlaitmnn. The mouth is here situated between two pores on 

 each aide, through which a spicular process comes out It occurs in 

 the frontal sinuses, lungs, and surface of the lirer of the Mammalia 

 (dog, horse, wolf), and in reptiles. 



6. PolyHoma. This genus has six anterior pores, besides a ventral 

 and posterior one. It mostly occurs in the throat and branchiae of 

 fishes, and the bladder of frogs ; but one species, the P. junyuicoln, 

 was discovered by T rentier in the cavity of an indurated adipose 

 tubercle, in the left orarium of a female aged 20, who had died in 

 child-bed. The tumour, which was apparently formed entirely of 

 indurated fiat, was of a reddish colour, and hollow within ; the cavity 

 was nearly filled by the above-named worm, which was about half 

 an inch in length, and between one and two lines in width. 



The 4th order, Acimlkorrphala, contains but one genus, Krhino- 

 rkynckiu, to which belong numerous species occurring in all classes 

 of vetebrate animals except man. They are generally found in the 

 intestinal canal, fixed between iU membranes, and occasionally even 



in the peritoneal cavity ; they have also been found in the neck under 

 the skin. 



We now come to the last and most highly-organised group of the 

 Entotoa, the Nematoidta, which contains a greater number of genera, 

 and includes more species inhabiting the human body than any of 

 the preceding. It has been divided into 11 genera, namely : 



1. Pilaria. These are of nearly equal thickness throughout their 

 whole length. They occur in all parts of the Verttbrata, though 

 principally in the cellular membrane ; they are also even found in 

 insects and their larva;. 



2. Trithotoma. On its anterior extremity, which is very thin, is 

 the mouth, resembling a minute point It is found in Mammaiin 

 birds, and A mpAtoia, between the coats of the stomach, in the intes- 

 tines, and the urinary bladder. 



8. Trickoctphalut. This genus differs from Pilaria in the capillary 

 form of the anterior part of the body, and in its swelling out behind. 

 It occurs principally in the accum of the Mammalia. 



4. Osyuri* is characterised by being subulate posteriorly, having 

 the mouth orbicular, and the penis in a sheath. The Atcarii rermi- 

 cularit is included in this genus by Bremser. 



5. Cucullanm is attenuated posteriorly. It occurs in the intestines 

 and abdomen of reptiles and fishes. 



6. Spiroptera is attenuated at each end. It occurs under the 

 nictitating membrane of birds, in various parts, of fish, and is said to 

 have been found in the urinary bladder of man. 



7. Phytaloptera is attenuated at both extremities ; the tail of the 

 male is bent downwards, winged, and furnished below with a sort 

 of bladder. The species are found in the stomach of Mammalia, birds, 

 and reptiles. 



8. Stronpylui. This has both ends attenuated : the tail of the 

 male termintes in what Kudolphi calls a bursa, and through this tho 

 penis passes out It occurs frequently in various situations in tin- 

 three first classes of vertebrate animals. 



9. Atcarii. This genus, which is the most numerous of the intes- 

 tinal worms, 80 species having been already described, has the 

 extremities attenuated, the mouth furnished with three valves or 

 tubercles, and the penis double. The species occur in almost every 

 part of the bodies of vertebrate animals. 



10. Ophiatluma ia attenuated at the extremities, and has the mouth 

 furnished with two lips. It is found in the intestines of Mammalia 

 and fishes. 



11. Liorhynchtu has the mouth at the end of a sort of erectile nnd 

 polished tube. It occurs in the stomach and intestines of some of tho 

 Mammalia and of many fishes. 



In the above list of the genera of the cavitary, intestinal, or round 

 worms, we have not made any particular mention of the species 

 parasitic in man, and as several of them possess considerable interest, 

 we need no apology for giving a short description of them. We may 

 begin with the genus Pilaria, three species of which are enumerated 

 as human inhabitants, though two of them have been only once 

 detected. The Guinea- Worm (Filaria Mcdintntit) frequently occur* 

 in hot climates, but the countries where it most abounds are Arabia, 

 Upper Egypt, Abyssinia, and Guinea. Its general habitation is the 

 subcutaneous cellular tissue, particularly of the lower extremities ; l.u' 

 it is also found in the scrotum, and very rarely beneath the tunica 

 conjunctiva of the eye. The length of this worm varies from six 

 inches to twelve feet : it in about as thick as the string of a violin. 

 Its colour is generally white, but occasionally brown ; it in round, and 

 of nearly equal dimensions in its whole length, but becomes a little 

 attenuated towards the anterior extremity. The tail of the male in 

 obtuse, and armed with a spiculum ; in the female it is acute and 

 bent. The mode of development of this entozoon is unknown. It 

 seems that it may exist for many mouths without being detected, 

 cases occurring where it has not been discovered till more than a 

 twelvemonth after leaving the country where it was contracted. 

 After a time it produces irritation ; in some point of the skin a vesicle, 

 pustule, or small abscess forms, breaks, and then the end of the w m-m 

 makes it appearance, which may be taken hold of, and cautiously and 

 gradually extracted. If the Filaria is broken, the portion remaining 

 beneath the skin dies, and produces inflammation, sinuous abscesses, 

 and often great constitutional disturbance, requiring amputation of 

 the limb. It seems to be capable of slowly shifting its situation in 

 the cellular membrane. According to Kudolphi, its Doming out 

 through the skin is not to be attributed to perforation of that mem- 

 brane, which it is not at all cajiable of effecting, but only to the 

 irritation which it excites in approaching the integuments. It seems 

 sometimes to affect people within the tropics in an endemic or even 

 epidemic form, nearly half the men in a regiment having been attacked 

 at the same time by it This species has been mentioned as having 

 been found occasionally beneath the conjunctiva of the eye; Imt 

 another, and much smaller kind, has been detected within the eyeball 

 itself, namely the F. Oculi Iluinnni, wliirh Nordman met with in the 

 liquor Morgagnii of the capsule of the crystalline lens of a man who 

 had had the operation of extraction for cataract performed. Two 

 minute worms were discovered coiled up together. This species 

 differs from the large Film-in (' mud in the eye of tho horse. The third 

 species is the P. bronchialu, which was once detected in the enl ui/'-<! 

 bronchial glands of a man by Treutler; its length woa about an inch. 



