Part 43

287. VORTICELLA SPUTARIUM. V. ventrosa, apertura orbiculari, ciliis longis raris excentricis. Round and prominent, with an orbicular aperture, and long hairs radiating as from a center.

This is one of the most singular of the microscopic animalcula; when viewed sidewise, it is sometimes nearly cylindrical, but somewhat tapering towards the hinder-part, and having a broad pellucid edge; viewed from the top, it has sometimes a broad face or disc furnished with radiating hairs, the under part contracted into a globular shape, of a dark green colour, and filled with small grains. It was found in October with the lesser lemna.

288. VORTICELLA NIGRA. V. trochiformis nigra. Plate XXVII. Fig. 36 and 37. Top-shaped black vorticella.

This may be seen with the naked eye, appearing like a black point swimming on the surface of the water; the microscope exhibits it as a minute conical body, opake, obtuse, and ventricose at one extremity, and acute at the other. When it extends the extremities, two small white hooks become visible; by the assistance of these it moves in the water, and it is probable from some circumstances that they inclose a rotatory organ. It moves continually in a vacillating manner on the top of the water. It is found in August, in meadows that are covered with water. _a_, the rotatory organ; _b_, the two small hooks; _c_, the acute end.

289. VORTICELLA MULTIFORMIS. V. viridis, opaca, varia, vesiculis sparsis. Green, opake, variable vorticella, with vesicles scattered about the body.

The vesicles of this vorticella are larger; in other respects it so much resembles the preceding one, that a further description is unnecessary. It is found in salt water.

290. VORTICELLA POLYMORPHA. V. multiformis, viridis, opaca. Plate XXVII. Fig. 33, 34, 35. Many-shaped vorticella, green, opake.

To the naked eye it appears like a green point, moving with great agility; but, when viewed through a microscope, it assumes such a variety of forms, that they can neither be exhibited to the eye by drawings, nor described by words; it is truly one of the wonders of nature, astonishing the mind, fatiguing the eye, and continually exciting the beholder to ask,

“Quo teneam vultus mutantem protea nodo?”

The body is granulous, and a series of pellucid points is sometimes to be observed, as at _b b_.

Fig. 33, 34, 35, represent this vorticella in three different forms; _a_, the fore-part; _g_, the hind-part; _c_, the fore-part simple; _d_, the fore-part turned in or doubled.

291. VORTICELLA CUCULLUS. V. elongata, teres, apertura oblique truncata. This vorticella is long, round, the aperture or mouth obliquely truncated.

This being visible to the naked eye, may likewise be ranked among the larger vorticellæ. The body is somewhat conical, of a dingy red colour; its shape has been compared to that of a grenadier’s cap.

292. VORTICELLA UTRICULATA. V. Viridis, ventricosa, productilis, antice truncata. Green vorticella, the belly round and prominent, capable of being lengthened or shortened; the fore-part truncated, much in the shape of a common water-bottle; the neck is sometimes very long, at others, very short, and filled with green molecules.

293. VORTICELLA OCREATA. V. subcubica, infra in angulum obtusum producta. This vorticella is somewhat of a cubical figure, the under part bent in an obtuse angle.

It is a very singular animalculum, in shape somewhat resembling the lower part of a boot; the apex of the upper part or leg is truncated and ciliated, the heel pointed, and the foot round. It is to be found in rivers, though very rarely.

294. VORTICELLA VALGA. V. cubica, infra divaricata. Cubical vorticella, the lower part divaricated.

This is as broad as long, and filled with grey molecules, the apex truncated and ciliated; both angles of the base projecting outwards, one somewhat like a wart, the other like a finger. It is found in marshy waters.

295. VORTICELLA PAPILLARIS. V. ventricosa, antice truncata, papilla caudali et laterali hyalina. Big-belled vorticella, the fore-part truncated, with a papillary tail, and a splendid papillary excrescence on the side. It is found in marshes where the conferva nitida grows.

296. VORTICELLA SACCULUS. V. cylindracea, apertura repanda, margine reflexo. Cylindrical vorticella, the aperture broad and flat, the edge turned down.

A thick animalculum, of an equal diameter everywhere, and filled with molecules; the edge of the mouth is bent back, the hinder-part obtuse, sometimes notched and contracted, with cilia on both sides of the mouth.

297. VORTICELLA CIRRATA. V. ventrosa, apertura sinuata, cirro utrinque ventrali. Big-bellied vorticella, the aperture sinuated, two tufts of hair on each side of the belly. It is found in ditch water.

298. VORTICELLA NASUTA. V. cylindracea, crateris medio mucrone prominente. Plate XXVII. Fig. 38, 39. Cylindrical, with a prominent point in the middle of the cup.

An animalculum that is invisible to the naked eye; but the microscope discovers it to be furnished with a rotatory organ, which encompasses the middle of the body.

It is pellucid, cylindrical, of an unequal size; the fore-part, _a_, truncated and ciliated, and a triangular prominence, _e_, in the middle of the aperture; the hind-part is obtuse, with a point on each side of the middle of the body. This is the appearance of the little creature when in motion; but when the water is nearly exhaled, some further parts of its structure are rendered visible; two rotatory organs are now observable; one on the fore-part, and the other encompassing the middle of the body, _h h_; the hairs of the latter are in vehement motion. Other fascicles of moving hair may likewise be observed, and the variegated and quick motion of this apparatus is very surprizing, especially if the animalculum be big with young, moving at the same time within the mother.

299. VORTICELLA STELLINA. V. orbicularis, disco moleculari, peripheria ciliata. Orbicular vorticella, with a molecular disc, and ciliated margin.

300. VORTICELLA DISCINA. V. orbicularis, margine ciliato, subtus convexo-ansata. Plate XXVI. Fig. 8, 9, 10. Orbicular vorticella, the edge ciliated, with a kind of convex handle on the under-side.

301. VORTICELLA SCYPHINA. V. craterformis, crystallina, medio spærula opaca. Bowl-shaped vorticella, crystalline, with an opake spherule in the middle.

302. VORTICELLA ALBINA. V. cylindrica, postice acuminata. The fore-part cylindrical, the hinder-part tapering, and ending nearly in a point.

303. VORTICELLA FRITILLINA. V. cylindrica vacua, apice truncata, ciliis prælongis. Empty cylindrical vorticella, the apex truncated.

304. VORTICELLA TRUNCATELLA. V. cylindrica, differta, apice truncata, cyliis breviusculis. Cylindrical vorticella, stuffed or filled, the apex truncated, with very short cilia.

This is one of the larger kind of animalcula; the body is crystalline, and replete with black molecules; the skin is perfectly smooth and colourless, the hinder extremity rounded, and the anterior truncated; at this extremity there is a large opening thickly ciliated, which serves as a mouth.

305. VORTICELLA LIMACINA. V. cylindrica, truncata, ciliis bigeminis. Plate XXVII. Fig. 60. Cylindrical truncated vorticella, with two pair of cilia.

306. VORTICELLA FRAXININA. V. gregaria, cylindracea, oblique truncata, ciliis bigeminis, apice margine fissa. Gregarious cylindrical vorticella, obliquely truncated, with two pair of cilia, and a fissure or notch at the upper edge.

The greater part of the body is cylindrical; the hinder-part rather tapering, and filled with opake molecules; towards the upper end it is transparent; within the edge, at the top are two small tubercles, from each side of which proceed a pair of small hairs.

307. VORTICELLA CRATEGARIA. V. composita, floribus muticis globosis; tentaculis binis, stirpe ramosa, Plate XXII. Fig. 40. Compound, with globous naked florets, two tentacules, and a branched stem. For an ample description of this animalculum, see page 400.

308. VORTICELLA HAMATA. V. bursæformis, margine aperturæ aculeis rigidis. Plate XXVII. Fig. 40. Purse-formed; the edge of its aperture or mouth set with rigid points.

It is not ciliated, nor have any hairs been discovered upon it; the body is granulated, the fore-part broad and truncated, the hinder-part obtuse, and capable of being contracted or extended. _a_, the rigid points.

309. VORTICELLA CRATERIFORMIS. V. subquadrata, ciliorum fasciculis etiam postice. Plate XXVII. Fig. 40, 41. Approaching somewhat to a square figure, with fascicles of cilia even at the hinder-part.

A lively animalculum, pellucid, round, longer than it is broad, with convex sides; the head is situated at the large end, the skin smooth, and some traces of intestines may be discovered with difficulty. There is a considerable opening surrounded with hair at the larger end, and the filaments composing it are in continual motion. Two of them are sometimes seen joined together, as at Fig. 41, and full of small spherules; in this state they draw each other alternately different ways, the surface is smooth and the hairs invisible. _e_, moveable cilia.

310. VORTICELLA CANALICULATA. V. dilatata, pellucida, latere inciso. Dilated, pellucid, with an incision in the side.

To the naked eye it appears as so many white points adhering to the sides of the glass; when magnified, the anterior part is narrower than the hind one; in the side a kind of incision may be perceived, and the hind-part is a little notched towards the middle; it is furnished with a rotatory organ, with which it excites a continual whirling motion in the water.

311. VORTICELLA VERSATILIS. V. elongata spiculiformis, mox urceolaris. Long spear-formed vorticella, but which often changes its shape into a pitcher-like form.

A pellucid, gelatinous animalculum, of a greenish colour, furnished with small radii, particularly about the circumference, which gives it the appearance of a minute water hedge-hog.

312. VORTICELLA AMPULLA. V. folliculo ampulaceo, pellucido, capite bilobo. Plate XXVI. Fig. 4 and 5. This vorticella is contained in a pellucid bottle-shaped bag, the head divided into two lobes.

Little more need be said to enable the reader to know this animalculum, if he should meet with it, than to observe that the bag is nearly in the shape of the common water-bottle, and that the animalculum is sometimes to be observed at the bottom of it, sometimes nearly filling it.

313. VORTICELLA FOLLICULATA. V. oblonga, folliculo cylindraceo hyalino. Oblong vorticella, in a bright cylindrical bag.

This animalculum is gelatinous and cylindrical; when at its greatest extension, the base appears attenuated, and the apex truncated.

314. VORTICELLA LARVA. V. cylindrica, apertura lunata, spinis caudalibus binis. Cylindrical, the aperture somewhat in the shape of a crescent, two small thorny points projecting from the hinder-part.

The head, the trunk, and the tail, may be easily distinguished from each other. It is of a clay-colour, the aperture ciliated; with a globular projection at times appearing to proceed from it.

315. VORTICELLA SACCULATA. V. inverse conica, apertura lunata, trunco postice bidentato, cauda elongata biphylla. Plate XXVII. Fig. 42 and 43. This vorticella is in the shape of an inverted cone, with an aperture the figure of a crescent; the lower part of the trunk is notched, forming as it were two teeth; the tail biphyllous. Each of these parts is surrounded with a loose bright skin, the head is divided from the trunk by a deep incision. _a a a_, small points projecting from the head; _b_, the cilia; _c_ and _d d_, the interior parts; Fig. 42, _l_, the little horn at the bottom of the trunk.

316. VORTICELLA AURITA. V. cylindrico-ventrosa, apertura mutica, ciliis utrinque rotantibus cauda, articulata biphylla. Cylindrical and big-bellied, the aperture destitute of hairs, both sides of it are furnished with rotatory cilia, the tail biphyllous.

317. VORTICELLA TREMULA. V. inverse conica, apertura lobata spinulosa, cauda brevi unicuspi. Somewhat of a conical shape; the mouth being divided into two parts which are set with small spines, and a point projects from the tail.

It is a pellucid crystalline ventricose animalculum, within the body on one side, there is a large clay-coloured oval mass, and a pellucid oval substance adjacent to it; the tail is articulated and very short.

318. VORTICELLA SERITA. V. inverse conica, apertura spinosa integra, cauda brevi bicuspi. Somewhat of the shape of a cone, the aperture set with spines, the tail short and divided into two points.

The body is muscular, pellucid, folding variously; the fore-part truncated; round the margin of the aperture are rows of hairs, but it has also stiffer hairs or spines continually vibrating, with which it draws in both animate and inanimate substances. It has some resemblance to the larger vorticella rotatoria, but is easily distinguished from it by its horned spiny aperture, and simple rotatory organ.

319. VORTICELLA LACINULATA. V. inverse conica, apertura lobata, setis binis caudalibus. Plate XXVII. Fig. 45. Shaped like an inverted cone, the aperture lobated, the tail small and furnished with two bristles, _d_.

The body is pellucid, cylindrical, and muscular; the apex about a third part down, drawn into a little neck; in the middle is a little lamina or triangular point; another of these is discovered when the aperture faces the observer, which makes it appear like a small flower. The hind-part, when in motion, is a little bent; it terminates in two minute bristles, which are seen sometimes united, at other times diverging. When the animalculum is swimming, its rotatory organ, _a_, may be seen; molecular intestines are visible; it moves with velocity in an oblique direction. It is found in pure water.

320. VORTICELLA CONSTRICTA. V. elliptico-ventricosa, apertura integra, cauda annulata biphylla. Elliptical ventricose vorticella, the aperture or mouth undivided, the tail annulated and forked.

There are two kinds of this vorticella; viz. one of a pale yellow, the other of a white colour; the head, the tail, and the trunk, are fully distinguished; a substance in motion has been perceived, which has been supposed to be the heart; they move by fixing their tail to the glass upon the stage of the microscope, and extending their body as much as possible; they then fix the fore-part to the place where they intend to move, and draw the hinder-part to it, proceeding thus alternately. They sometimes turn round about upon one of the points of their tail, at other times they spring forwards with a jerk. When at rest they open their mouths very wide; the lips are ciliated, in some of them two black globules are discovered.

321. VORTICELLA TOGATA. V. subquadrata, apertura integra, spinis caudalibus binis, plerumque unitis. Square vorticella, the aperture not divided, the tail consisting of two long spines, which are sometimes so united as to appear as one.

The body is convex, of a dark colour, and filled with molecules; the middle part is pellucid, the hinder-part rather broader than the fore-part; the latter is ciliated, and the tail formed of two very thin pellucid spines, which are somewhat curved and much longer than the body.

322. VORTICELLA LONGISETA. V. elongata, compressa, setis caudalibus binis longissimis. Long vorticella, flat, the tail formed of two very long bristles.

The fore-part sinuated, and set with minute cilia; the two bristles which constitute the tail are long, but one is longer than the other.

323. VORTICELLA ROTATORIA. V. cylindrica, pedicello collari, cauda longa quadracuspi. Plate XXVI. Fig. 1, 2, 3, 6, 7, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, and Plate XXVII. Fig. 46, 47, 48, and 49. Cylindrical vorticella, with a little foot projecting from the neck, a long tail furnished with four points.

Brachionus corpore conico subæquali. Hill Hist. Anim. Brachionus corpore conico toruloso. Ibid. Brachionus. Pallas Zooph. 50. Joblot Micros, part 2, p. 77, pl. 10, fig. 18; and p. 96, pl. 5, A B C D E K. Adams’s Microgr. Illustr. p. 148, pl. 40, fig. 255. Leeuwenhoeck Contin. Arc. Nat. p. 386, fig. 1, 2. Baker’s Micros. made easy, p. 91-93, pl. 8, fig. 6, 7, 8. Ibid. Empl. for the Micr. p. 267-294, pl. 11, fig. 1 to 13. Spallanz. Opusc. Phys. 2, p. 301, 315, pl. 4, fig. 3, 4, and 5. Rozier Journal Physique, 1775, p. 220.

This animalculum has long been known by the name of the wheel animal; in the description of which no person appears to have succeeded so well as Baker; and to him every writer has since referred for an ample account of this curious little being. What I shall now say on the subject will be chiefly extracted from the same source of information, with such alterations and additions as appear to be necessary to render his account more complete.

I shall begin with observing, that Müller’s wheel animal differs in some respects from that of Baker’s; first, with regard to the rotatory organs which are extended on the back like ears; secondly, the two little splendid substances within the body; and thirdly, the two black points near the top of the head, which are probably the creature’s eyes.

This little animal is found in rain water that has stood for some days in leaden gutters; in the hollows of lead on the tops of houses; or in the slime and sediment left in rain water; they are also sometimes to be met with in ditches and amongst duck-weed.

It has been called the wheel animal, because it is furnished with a pair of instruments, which in figure and motion resemble wheels. It appears only as a living creature when immersed in water; notwithstanding which, it may be kept for many months out of water, and in a state of perfect dryness, without losing the principle of life. When dry, it is of a globular form, about the size of a grain of sand, and without any apparent signs of life. If it be put into water, in the space of half an hour a languid motion begins, the globule turns itself about, lengthens itself by slow degrees, and becomes very lively; in a short time it protrudes its wheels, and swims about in search of food; or else, fixing itself by its tail, brings the food to it by its rotatory organs, which throw the whole circumjacent fluid into a violent commotion; when its hunger is satisfied, it generally becomes quiescent, and sometimes resumes its globular form.

If the water that is found standing in gutters of lead, or the sediment it has left behind, has any appearance of a red or a dark brown colour, little doubt need be entertained of its containing these animalcula. In the summer season, if a small quantity of this dust be put into water, and placed under a microscope, it seldom fails of discovering a great number of minute reddish globules, which are, in fact, the animals themselves. It will be best to view them first with the third or fourth magnifiers, and afterward apply those possessing greater powers.

The motions of this little creature somewhat resemble those of a caterpillar; like many of those insects, removing itself from place to place by first fixing the tail to some substance, then extending the whole body, fixing the head, and afterward drawing the tail to it; by these alternate actions it moves with some degree of swiftness.

This animal frequently changes its appearance, and assumes a very different form; for, the snout being drawn inwards, the fore-part becomes clubbed, and immediately dividing, exhibits to our view two circular instruments set with minute hairs, that move very briskly, sometimes in a rotatory, at other times in a kind of trembling or vibratory manner. An aperture or mouth is also perceived between the two semicircles; whilst in this state, the animal may often be perceived swimming about in pursuit of food.

The most distinguishing parts of this animalculum are, the head, the thorax, and the abdomen. It differs from any other creature hitherto described in the wonderful form and structure of its head; the sudden changes of which from one form to another are equally surprizing and singular; from being of a very taper form, it becomes almost instantaneously as broad as any part of its body, and protrudes an amazingly curious machinery formed to procure its food.

The circular bodies which project from the animal have much the resemblance of wheels, appearing to turn round with considerable velocity, by which means a very rapid current of water is brought from a great distance to its mouth. As these wheels are very transparent, the edges excepted, which are set with fibrillæ, as cogs to a wheel, it is difficult to determine how the rotatory motions are performed, or whether their figure be flat, concave, or conical; be this as it may, they are protruded from a couple of tubular cases, into which they can be again withdrawn, at the will and pleasure of the animal. They do not always turn the same way, nor with the same degree of velocity, sometimes moving in opposite directions, at other times both one way. The figure varies according to the degree of their protrusion, as well as from other circumstances. They appear occasionally like minute oblong squares, rising from the periphery of a circle; at other times they terminate in sharp points, and sometimes they are curved, bending the same way like so many hooks; now and then the ends appear clubbed, or in resemblance like a number of small mallets.

When the fore-part of this creature is first seen to open or divide, the parts, which when fully protruded resemble wheels, seem only like a couple of semicircles, the edges of which are set with little spiculæ, having a nimble, and continually vibrating motion upwards and downwards, for the purpose of agitating the water, each wheel being in this case doubled, or like a round piece of paper folded in the middle.

When the wheels are in motion, the head appears very large in proportion to the size of the animal; and though it is then everywhere transparent, yet a ring or circle, more particularly distinguished by its brightness, may be perceived about the middle of the forehead, from whence many vessels are seen to originate.

The thorax or breast is united to the head by a short annular circle or neck; the size of the thorax is nearly one-sixth part of the whole animalculum. In it the heart is distinctly seen; being placed nearly in the center, the diastole and systole cannot fail to attract the eye of every attentive observer; the alternate dilatation and contraction is very perceptible through the back of the animal, being performed with great strength and vigour. It appears to be composed of two semilunar parts, which in the time of contraction approach each other laterally, and form between them a figure somewhat like a horse-shoe, whose upper side is flat, the under one convex. In the diastole, these two parts separate; the separation begins exactly in the middle of the lower part next the tail. In each of the semilunar parts there is a cavity, which closes when they come together; and opens when they separate.

The motion of the heart is communicated to all the other parts of the thorax, and indeed through the whole animal. It is necessary however to remark, that this motion is sometimes suspended, or at least quite imperceptible, for two or three minutes, after which it re-commences, and goes on with the same vigour and regularity as before. From the under part of the thorax a small transparent horn proceeds, which cannot be seen unless the insect turns on its back or side.