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TADPOLE

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Originally appearing in Volume V26, Page 354 of the 1911 Encyclopedia Britannica.

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TADPOLE , a See also:

TERM

term often, but wrongly, applied indiscriminately to all Batrachian larvae. It is absurd to See also:

CALL (from Anglo-Saxon ceallian, a common Teutonic word, cf. Dutch kallen, to talk or chatter)

call the larva of a See also:

NEWT (a corrupted form from " an evet " or " an effet," a term of Anglo-Saxon origin, still used in many parts of England)

newt or of a Caecilian a tadpole, nor is the See also:

FREE

free-See also:

SWIMMING (from " swim," A.S. swimman, the root being common in Teutonic languages)

swimming embryo of a See also:

FROG

frog as it leaves the See also:

egg a tadpole. A tadpole is the larva of a tailless Batrachian after the loss of the See also:

EXTERNAL

external gills and before the See also:

EGRESS (Lat. egressus, going out)

egress of the fore limbs (except in the aberrant Xenopus) and the resorption of the tail. What characterizes a tadpole is the conjoined globular See also:

head and See also:

BODY

body, so formed that it is practically impossible to discern the limit between the two, sharply set off from the more or less elongate compressed tail which is the See also:

ORGAN

organ of propulsion. In describing tadpoles, the term " body " is therefore used as meaning head and body. The tail consists of a fleshy See also:

MUSCULAR

muscular portion bordered above and below by membranous expansions, termed respectively the upper and See also:

LOWER

lower See also:

crest, the former sometimes extending along the body. Except in a few aberrant types, which are mentioned below, the mouth is surrounded by a much See also:

DEVELOPED

developed See also:

LIP (a word common in various forms, to Teutonic languages, cf Ger. Lippe, Dan. laebe; Lat. labium is cognate)

lip like a See also:

FUNNEL (through an O. Fr. founil, found in Breton, from Lat. infundibulum, that through which anything is poured, from fundere, to pour)

funnel directed downwards, and is armed with a horny See also:

BEAK (early forms beke and becke, from Fr. bec, late Lat. beccus, supposed to be a Gaulish word; the Celtic bec and beq, however, are taken from the English)

beak not unlike that of a cuttle-See also:

fish. The characters offered by the circular lip are among the most important for the distinction of See also:

SPECIES

species. It may be entirely bordered by fleshy papillae, or these may be restricted to the sides, or to the sides and the lower border. Its inner See also:

SURFACE

surface is furnished with ridges beset with See also:

SERIES (a Latin word from serere, to join)

series of See also:

minute, bristle-like, erect, horny See also:

TEETH (O.E. Eel); plural of tooth, O.E. top)

teeth, each of which, when strongly magnified, is seen to be formed of a See also:

COLUMN (Lat. columna)

column of super-posed cones, hollowed out at the See also:

BASE

base and capping each other; the See also:

SUMMIT

summit or See also:

CROWN

crown of each of these cones is See also:

EXPANDED

expanded, spatulate, hooked backwards, and often multicuspid. The number of these columns is very See also:

GREAT

great. F.

E. Schulze has counted as many as 'too in the lip of Pelobates fuscus. The beak is made up of horny elements, like the labial teeth, fused together; its edge, when sufficiently magnified, is seen to be denticulate, each denticle representing the See also:

CUSP (Lat. cuspis, a spear, point)

cusp of a single tooth. The gills, See also:

BORNE, KARL LUDWIG (1786–1837)

borne on four See also:

ARCHES, COURT OF

arches, are See also:

INTERNAL

internal and enclosed in the branchial See also:

chambers. The arches See also:

bear on the See also:

CONVEX

convex See also:

OUTER

outer See also:

side the delicate arborescent gills, and on the See also:

CONCAVE

concave inner side develop a membranous septum with vermicular perforations, a See also:

SPECIAL

special sifting or filtering contrivance through which the See also:

WATER

water absorbed by the mouth has to pass before reaching the See also:

RESPIRATORY

respiratory See also:

ORGANS

organs of the branchial apparatus. The water is expelled from the branchial chambers by one or two tubes opening by one orifice in most Batrachians. This orifice is the spiraculum, which is lateral, on the See also:

LEFT

left side of the body, in most tadpoles, but median, on the See also:

BREAST (a word common to Teutonic languages, cf. the Ger. Brust, possibly connected with an O. Sax. brustian, to bud)

breast or belly, in those of the Discoglossidae and of some of the Engystomatidae. All tadpoles are provided with more or less distinct lines of muciferous sensory crypts or canals, which stand in immediate relation to the See also:

NERVE (Lat. nervus, Gr. vevpov, a bowstring)

nerve branches and are regarded as organs of a special sense possessed by aquatic vertebrates, feeling, in its broadest sense, having been admitted as their possible use, and the See also:

FUNCTION

function of determining waves of vibration in the aqueous See also:

MEDIUM

medium having been suggested. In addition to these lines, all tadpoles show more or less distinctly a small whitish gland in the See also:

MIDDLE

middle of the head between the eyes, the so-called frontal gland or pineal gland, which in See also:

early stages is connected with the See also:

BRAIN (A.S. braegen)

brain. A glandular streak extending from the nostril towards the See also:

eye is the lachrymal See also:

canal. The eyes are devoid of lids. Owing to more or less herbivorous habits, the See also:

INTESTINE (Lat. intestinus, internal, usually in neuter plural intestina. from intus, within)

intestine is exceedingly elongate and much convoluted, being several times larger and of a greater calibre than after the See also:

METAMORPHOSIS

metamorphosis.

Its opening, the vent, is situated either on the middle See also:

LINE

line at the base of the tail, or on the right side, as if to See also:

BALANCE (derived through the Fr. from the Late Lat. bilantia, an apparatus for weighing, from bi, two, and lanx, a dish or scale)

balance the sinistral position of the spiraculum. The tail varies much in length and shape according to the species; sometimes it is rounded at the end, sometimes more or less acutely pointed, or even terminating in a filament. The See also:

SKELETON

skeleton is cartilaginous, and the See also:

SKULL

skull is remarkable for the very elongate suspensorium of the lower See also:

JAW (Mid. Eng. jawe, jowe and geowe, O. Eng. cheowan, connected with " chaw " and " chew," and in form with " jowl ")

jaw; the tail remains in the notochordal See also:

CONDITION (Lat. condicio, from condicere, to agree upon, arrange; not connected with conditio, from condere, conditum, to put together)

condition, II no cartilages being formed in this organ, which is destined to disappear with the gills. The See also:

HIND

hind limbs appear as buds at the base of the tail, and gradually attain their full development during the tadpole See also:

LIFE

life. The fore limbs grow simultaneously, and even more rapidly, but remain concealed within a diverticulum of the branchial chambers until fully formed, when they burst through the skin (unless the left spiraculum be utilized for the egress of the corresponding See also:

LIMB

limb). The above description applies to all See also:

EUROPEAN

European and See also:

North See also:

AMERICAN

American tadpoles, and to the great See also:

MAJORITY (Fr. majorite; Med. Lat. majoritas; Lat. major, greater)

majority of those known from the tropics. The following types are exceptional. The circular lip is extremely developed in Megalophrys See also:

MONTANA

montana, and its funnel-shaped expansion, beset on the inner side with radiating series of horny teeth, acts as a surface-See also:

FLOAT (in O. Eng. floc and flota, in the verbal form f eotan; the Teutonic root is flut-, another form of flu-, seen in " flow," cf. " fleet "; the root is seen in Gr. a-M e, to sail, Lat. pluere, to rain; the Lat, fluere and fluctus, wave, is not connect

float, when the tadpole rests in a See also:

VERTICAL (from Lat. vertex, highest point)

vertical position; the moment the tadpole sinks in the water the funnel collapses, taking on the See also:

FORM (Lat. forma)

form of a pair of horns, See also:

curling backwards along the side of the head; but, as they See also:

TOUCH (derived through Fr. toucher from a common Teutonic and Indo-Germanic root, cf. " tug," " tuck," O. H. Ger. zucchen, to twitch or draw)

touch the surface again, it re-expands into a See also:

REGULAR

regular See also:

PARACHUTE (from Ital. parare, to shield, protect; cf. " parasol," " parapet," and Fr. chute, a fall)

parachute. In some species of Rana and Staurois inhabiting mountainous districts in See also:

south-eastern See also:

ASIA

Asia, the larvae are adapted for life in torrents, being provided with a circular adhesive disk on the ventral surface behind the mouth, by means of which they are able to See also:

ANCHOR (from the Greek ayrcvpa, which Vossius considers is from 6yi17 , a crook or hook)

anchor themselves to stones. In some See also:

INDIAN

Indian and See also:

MALAY

Malay Engystomatids of the genera Callula and Microhyla, the tadpoles are remarkably transparent, and differ markedly in the structure of the buccal apparatus. There is no funnel-shaped lip, no horny teeth, and no beak. The spiraculum is median and opens far back, in front of the vent.

In the Aglossal Xenopus, the tadpoles are likewise devoid of circular lip, horny teeth, and beak, and they are further remarkable in the following respects: There is a See also:

long tentacle or See also:

BARBEL (Barbus vulgaris)

barbel on each side of the mouth, which appears to represent the " balancer " of Urodele larvae; the spiraculum is paired, one on each side; the fore limbs develop externally, like the hind limbs. Some tadpoles reach a very great See also:

SIZE

size. The largest, that of Pseudis paradoxa, may measure a See also:

FOOT

foot, the body being as large as a See also:

TURKEY

turkey's egg. The perfect frog, after transformation, is smaller than the larva. Pseudis was first described by See also:

MARIE

Marie Sibylle de See also:

MERIAN, MATTHEW (1593–1650)

Merian (1647—1717), in her See also:

WORK

work on the See also:

FAUNA

fauna of Surinam (published first in 1705 at See also:

Amsterdam, republished in Latin in 1719), as a frog changing into a fish. Among European forms, some tadpoles of Pelobates attain a length of seven inches, the body being of the size of a See also:

hen's egg. The tadpole of the North American See also:

bull-frog See also:

MEASURES

measures six inches, and that of the Chilian Calyptocephalus gayi seven and a See also:

HALF

half inches. Notes upon the Tadpole of Xenopus laevis," P.Z.S., 1894, p. 101 ; S. See also:

Flower, " Batrachians of the Malay See also:

Peninsula and See also:

SIAM (known to its inhabitants as Muang Thai)

Siam," P.Z.S., 1899, p. 885 ; H. S.

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