TERELSIINTHA.j 



MUSEUM OF ANIMATED NATURE. 



423 



propelled along. The anterior part contains more- 

 over a proboscidiform oesophriu;us, with a mouth 

 havins: a siickin!;-glass marsjin continued into a 

 stomach surrounded with green hepatic granules (lu- 

 diraents of the liver), and sometimes a second filled 

 with air. Besides this, there is at the lower part a 

 glandular mass, probably the egg-vessel, and which 

 is in more or less immediate connexion with the 

 cirrhiform prolongation. 



" The Diphydes," as M.de Blainville remarks," are 

 very transparent animals, so that it is ol'ten very 

 difficult to distinguish them in the sea, and even in 

 a certain quantity o!' water taken from it. It is 

 especially at extremely great distances from the 

 shore that they are met with in the seas of warm 

 climates, and often very numerous. They float and 

 swim apparently in all directions, with the anterior 

 or nuciean extremity foremost, getting rid of the 

 water they take in by the contraction of the two 

 subcartilas;inous parts; their aperture consequently 

 is always directed backwards. When the two nata- 

 tory organs are equally provided w;ith a special 

 cavity, it is probable that the locomotion is more 

 rapid : it can finally be executed by either the one 

 or the other in proportion to their size. The pos- 

 terior portion is attached to the nucleus with so little 

 solidity that it often becomes detached from it acci- 

 dsntally ; hence M. Botta believed that an entire 

 Diphyes w.-is only formed by one of those parts, he 

 having but rarely found these animals complete. 

 During locomotion the cinhigerous production, or 

 egg-tube, apparently floats extended backwards, 

 lodging itself partly in a gutter into which the in- 

 ferior edge of the posterior natatory organ is hol- 

 lowed out ; but it has not the same length, the ani- 

 mal being able to contract it powerfully, even to the 

 extent of drawing it entirely inwaids. From this it 

 is evident that the organ is muscular ; what, how- 

 ever, is remarkable is that throughout its length, 

 and placed at tolerably regular intervals, are found 

 organs which MM. Qiioy and Gaimard regarded as 

 suckers, and which possessed in fact the faculty o£ 

 adhesion and bringing the animal to anchor, as M. 

 Botta was satisfied. I dare not decide what this 

 organ is ; but I am strongly inclined to believe 

 either that it is a prolongation of the body ana- 

 logous to that in the Physsophorae, or if not an egg- 

 tiibe, is at least an assemblage of young individuals." 

 M. Eschscholtz regarded it as a nutritive canal; 

 either simple, or provided with one or with several 

 suckers. M. de Blainville divides the Diphyida (or 

 Diphydse), first, into such as have only a single 

 cavity in the anterior part ; secondly, into those 

 whose anterior part is furnished with two cavities ; 

 thirdly, into doubtliil species, with only one part, as 

 far as known. Of these three minor groups we shall 

 give several examples, which will show what strange 

 and unexpected forms are presented by animals of 

 the lower orders of creation. They are repre- 

 sented so as to show the two parts in their natural 

 union, as well as apart, and also in several aspects. 



To the first group belong the following species : — 



Fig. 3889, Cucubalus cordiformis, of a heart- 

 shape : the animal swims vertically. 



Fig. 3890, Cucullus Doreyanus (Quoy and Gaim- 

 ard), from the seas of New Guinea. Jt is closely 

 allied to the preceding form. 



Fig. 3891, Navicula sagittata (De Blainville) ; 

 Cymba sagittata (Quoy and Gaimard). This sin- 

 gular species is found in the Straits of Gibraltar. 

 The term Cymba has been appropriated by Mr. 

 Broderip to a genus of shells (Volutidae), and must 

 therefore be suppressed in this instance. 



Fig. 3892, Cuboides vitreus, from the Straits of 

 Gibraltar : a, the natural size ; b, magnified. 



Fig. 3893, Enneagone hyalina (Quoy and Gaim- 

 ard) : 1, 1 a, and 1 b, the animal under difl'erent 

 aspects ; 1 c, the visceral part ; 1 d, the nucleus. 



Fig. 3894, Amphiroa alata (Lesueur), from the 

 seas of Bahama: 1, 1 a, the animal in two aspects ; 

 I b, its nucleus extracted. 



The second group, containing species whose an- 

 terior part is furnished with two distinct cavities : — 



Fig. 3895, Calpe pentagona, from the Straits of 

 Gibraltar: 1, the animal in profile ; 1 a, the under 

 side; 1 b, the nucleus. 



Fig. 3896, Abyla trigona, from the Straits of 

 Gibraltar: 1, the anterior view ; 1 a, the posterior; 

 ] b, the visceral portion. 



Fig. 3897, Diphyes Bory (Quoy and Gaimard) ; 

 Diphyes Campanulifera (Eschscholtz). This species 

 is spread in all seas, and is the most common species. 

 1, the entire animal, profile ; 1 a, the anterior part 

 of the same ; 1 b, the posterior part : 1 c, the entire 

 animal, magnified ; 1 d, posterior part of the same. 

 For the account of an allied species, D. elongata, 

 taken on the coast of Ireland, by G. C. Hyndman, 

 Esq., see the ' Ann. and Mag. of Nat. Hist.,' May, 

 18-tI, p. 1&4, et seq. 



The third group, containing doubtful species, or 

 those with one part only, and respecting which our 

 information is very limited : — 



Kig. 3898, Pyramis tetragona. Of this nothing 



is known beyond what can be collected from a 

 description and figure by M. Otto. 



Fig. 3899, Praia dubia ; this singular animal is 

 rather solt, of a subgelatinous structure, and very 

 transparent ; it is divided by a longitudinal furrow, 

 and has a shallow cavity with a rounded aperture. 



Fitf. 391K), Tetragona hispidum, with details. M. 

 de Blainville regards this as nothing more than the 

 posterior part of a true Diphyes. 



Fig. 8u01, Sulculeolaria (juadrivalvis, from the 

 Mediterranean. M. de Blainville is strongly in- 

 clined to believe that this is not an entire animal, 

 but a portion of Calpe. 



Fig. 3902, Galeolaria australis. According to 

 M. de Blainville, this animal approximates to- 

 wards Beioe. 



Fig. 3903, Rosacea Ceutensis : this species is 

 suborbicular in form, very soft and transparent, with 

 a single terminal aperture, whence proceeds a cir- 

 rhiform process. 



Fig. 3904, Noctilucamiliaris. This little animal is 

 provisionally placed among the Diphyida. It was 

 first observed by M. Surreray, in the sea at Havre, 

 and in the dock and basins it occurs in such numbers 

 as to form not unfrequently a film on the surface of 

 the water. It is about the size of a pin's head, with 

 a moveable proboscis, which it agitates in all direc- 

 tions, and by means of which it executes its deli- 

 berate aquatic evolutions. This proboscis is tubu- 

 lar, and appears to be composed of annular fibres ; 

 it is in fact an organ of nutrition as well as of 

 locomotion. The Nociiluca is as transparent as 

 crystal, and from its phosphorescence is extremely 

 brilliant at night, gleaming like a sparkling diamond, 

 and where myriads are crowded together giving ef- 

 fulgence to the water. Us splendour is the greatest 

 in stormy but hot weather ; in winter its phospho- 

 rescence is diminished, and lost when the wind is 

 from the west. 



Another form of this group is presented by Dolio- 

 lura Mediterraneum. This animal, found in the 

 Mediterranean, appears to consist of nothing more 

 than a gelatinous hyaline cylindrical body resem- 

 bling a barrel in shape, with a large opening 

 at each extremity ; and it is stated to swim by 

 alternately absorbing and ejecting the water from 

 the two apertures. It is not improbable that the 

 Doliolum may be either the young of some species 

 unascertained, or a portion of some other diphyidous 

 animal, still retaining its vitality. The fact is that 

 the history of the Diphyida is yet involved in great 

 obscurity, and a series of observations are requisite 

 before we can hope to have the diflSculties cleared 

 up in which their structure and economy are en- 

 veloped. The little known only tends to excite our 

 astonishment. 



CLASS STERELMINTHA 



(Parenchymatous Worms). Most of the Sterel- 

 mintha inhabit as parasites the bodies of other 

 animals, and from the fluids of those bodies derive 

 their nutriment. They are not however confined 

 to one given locality : it is not only in the alimentary 

 canal that they take up their residence, but in the 

 substance of the brain, in the abdominal cavity, in 

 vessels of the liver, in the cellular tissue, and in the 

 substance of the muscles. They infest quadrupeds, 

 birds, fishes and reptiles, nor is man himself ex- 

 cluded. In many cases their presence proves ulti- 

 mately fatal, and is always connected with a diseased 

 condition. The Sterelmintha differ in size and exter- 

 nal form ; some being microscopic, others attaining to 

 the length of many yards. Their structure is simple, 

 but that of some much more so than that of others. 



The Sterelmintha, or Parenchymatous Entozoa 

 of Cuvier, are divided into four groups or orders : 1, 

 Cestoidea ; 2, Taenoidea ; 3, Trematoda ; 4, Acan- 

 thocephala. 



In the Cestoidea the structure is very simple. 

 The only genus, Ligula, comprehends certain worms 

 of a flat riband-like form, striated once longi- 

 tudinally, and repeatedly in a transverse direction. 

 These worms inhabit the abdominal cavity of birds, 

 but more especially of fishes, and prove fatal. One 

 species, the Ligula Cingulum, Rudolpbi, found in 

 the bream, attains to the length of five feet. There 

 are strange tastes among men, but few would think 

 of making this worm an article of diet ; yet Cuvier 

 says that in some parts of Italy it is regarded as an 

 agreeable viand; 



The Taenoidea present us with two distinct forms, 

 represented one by Ttenia, the Tapeworm, the 

 other by Cisticercus, or the Hydatids. 



The Taenia, of which certain species infest the 

 human subject, consists of a series of flattened 

 segments, commencing by a small square head, 

 the articulations succeeding which are small, and 

 gradually increase in size. The Taenia solium is 

 generally met with in England ; and the Taenia lata 

 in Russia, Poland, Switzerland, and, we believe, 

 America: a species. Taenia lamelligera, Owen, oc- 

 curs in the Flamingo. 



In TiBnia solium the mouth is placed in the centre 



of a square head surrounded with minute hooks; 

 and four suckers occupy each angle respectively. 

 By means of these hooks and suckers, the animal 

 is enabled to adhere to the lining membrane of the 

 small intestines, and there imbibe chyle. Each 

 segment, excluding those which immediately suc- 

 ceed, contains an arborescent apparatus in which the 

 multitudinous eggs are produced, so that, excepting 

 that of the nutritive apparatus, which is continued 

 throughout, each segment may be almost regarded 

 as a distinct being. Fig. 3900 represents portions 

 of the Ta-nia : 1, two joints of T. solium, magnified, 

 in one of which are seen the numerous eggs, which 

 pass through the egg-duct a; 2, some of the eggs, 

 magnified ; 3, the head, seen in front, with the mouth 

 in the centre surrounded by hooks, and by the 

 four suckers a a, two of which are alternately pro- 

 truded and retracted ; 4, the mouth with its hooks ; 

 5, two of the hooks, greatly magnified; 6, a sucker 

 greatly magnified. 



As the eggs are in myriads, andjret seldom more 

 than one Taenia infests an individual, the query arises, 

 what become of the germs thus multitudinously 

 produced? do they perish, or do they assume other 

 forms till placed by accident in a nidus favourable 

 to their due development ? 



The Hydatids, or Cysticerci, consist of a trans- 

 parent sac or globular vesicle containing a fluid ; 

 this vesicle has one or many heads, according to the 

 species. The ordinary Hydatid with one head (C. 

 longicoUis) is found often in enormous abundance in 

 the liver and abdominal cavity of quadrupeds, espe- 

 cially of the Ruminant order. The many-headed 

 Hydatid (Coenurus cerebralis) is common in the 

 biain of sheep, destroying the animal by pressure 

 on that organ, as it increases in size. They mul- 

 tiply by internal gemmules, and are often found 

 filled with smaller ones floating in the glairy 

 fluid. 



The Trematoda are represented by that singular 

 little sole-like parasite called the Fluke (Distoma 

 hepaticum), La Douve of the French, so common 

 in the liver of sheep. An allied genus, Polystoma 

 (Ilexastoma, Cuvier), presents us with several spe- 

 cies, two of which infest the human subject, one 

 (P. venanim) inhabiting the veins. 



To this section belong the Planarias, not parasitic, 

 found in fresh and salt water, where they creep on 

 the leaves and stems of plants like small black 

 flattened leeches: they feed on insects, worms, &c. 



We must here also place an allied group of ma- 

 rine worms, con.stituting the genus Nemertes of 

 Dr. Johnston ; they are very minute, and live under 

 stones in mud, between tide-marks. Both these and 

 the Planariae bear division with impunity. (' Mag. 

 of Zool. and Botan.,' vol. i. p. .529. )j 



A minute parasite, the Diplozoon paradoxum, is 

 found on the gills of the bream ; it is about three 

 lines long, and is somewhat cruciform in figure, or 

 rather resembles two distinct leech-like animals, 

 joined, as were the Siamese twins, by a median band 

 of union. It is in fact a double animal, of which 

 each side has the same parts, but the digestive ap-. 

 paratus is common to both. On each head are two" 

 suckers, and on each posterior extremity two oval 

 plates of membrane, with four suckers each ; and 

 thus is its adhesion to the slippery gill-covers of the 

 fish secured. 



The Acanthocephala includes only one distinct 

 genus, Echinorhynchus, of which the species termed 

 Echinorhynchus gigas is often found in abundance 

 in the alimentary canal of the hog. This Entozoon 

 is dioecious, the male and female being distinct. 

 The female exceeds the male, and attains to the 

 length of fifteen inches. The figure of this parasite 

 is elongated, tapering to the tail ; the head consists 

 of a retractile snout or proboscis, armed with four 

 circlets of sharp recurved spines, which serve as 

 holders ; it can be withdrawn by moans of retractor 

 muscles, and protruded at will. At the extremity of 

 this spine-armed proboscis is the mouth, a simple 

 suctorial orifice leading to a double nutritive canal. 

 The female produces eggs. 



With respect to the manner in which the Sterel- 

 mintha, as the Taenia, and especially the Hydatids, 

 the Distoma or Fluke, the Polystoma venarum, &c., 

 obtain admission to the brain, the substance of the 

 liver, the inside of the veins, and other localities in 

 which they are found, much obscurity exists. Their 

 spontaneous production is out of the question, — the 

 idea is an absurdity: we can only suppose that their 

 eggs or germs of great minuteness must exist in 

 some form at present unsuspected, and in a dormant 

 state, and be received into the alimentary canal, where 

 some become developed, and there remain, while 

 others are taken up by the lacteals, and carried ulti- 

 mately into the circulating system, where again some 

 develop themselves, while others are carried to va- 

 rious organs, as the brain and liver, in which they 

 meet with a suitable nidus for their perfection ; 

 and where, supplied with abundant nutriment, and 

 fostered by the animal heat, they grow inordinately. 



Various species are known to exist under the 



