130 



MUSEUM OF ANIMATED NATURE. 



[Tritoks. 



a sliort distance. Its general colour vRrics, bein)? 

 prev, brown, yellow, or olive, with markinits of a. 

 darker lint, mostly with a yellowish line down the 

 middle ol' the back. 



2330.— Thb Mitrkd Toad 

 (Birfo margnritlfer, Dand ). Olilophis margariti- 

 I'era, Cuv. ; Raiia marj^ritilera, Grael. 



Till* upeties, wliiuh i* a nalive of Braiil and Gui- 

 ana, is (listinjriiished by a crest on each side of the 

 head, extending from the anterior pari of the orbit 

 to the parotid plaml, whence a foid of skin runs 

 alonir each side of the body and down to the knee. 

 The skin of the hinder quarters of the hotly and 

 limlwis so loose and so little adherent to the muscles, 

 that the thighs and adjacent parts appear as if en- 

 shrouded in a sac. The general colour is olive, yel- 

 low, or brown; often nrilh raarblings of a deeper 

 lint. Under parts whitish, marbled with grey and 

 brown. The muzzle is pointed, the head trian- 

 gular. 



2331.— Thk Bi-coloured Toad 



(Enrn/stoma ovale, Fitzin.). Uana ovalis, Shaw; 

 Oxyrliynchus bicolor, Valenc, Guuriii, and Cuvier; 

 Stenocej>lia!us microps, Tschudi. 



This liltle reptile, remarkable for its small sharp- 

 pointed head, is a^iative of South America. 



Jn general the upjier parts are chestnut, the 

 under "parts white : sometimes the upper parts are 

 brown with a wash of slate l)lue ; the under parts 

 marbled or spotted with yellow and brownish red. 

 Some have the throat black, and in all there is a 

 whitish stripe along the back of the thighs. 



2332.— The Marbleb Toad 



(Upertklon nuirmoralum, Bibr.). Engystoma mar- 

 moratum, Cuvier. 



or this species little is known ; it was discovered 

 by Leschenault in the interior of India. 



' Its general colour is olive (green perhaps when 

 alive) marbled with large markings of brown. Under 

 parts white, excepting in the males, which have the 

 throat black. In this species there .iii.' (as an ex- 

 ception to the rule) a few small teeth in the palate. 

 The vocal sac of the male is capable of great ex- 

 tension. 



23.33. — Gessner's Palj»phrynos 



{Palaoplirynos Gessneri, Ttchudi). A fossil spe- 

 cies of toad, the relics of which, with those of 

 another species, I'elophilus Agassizii, are obtained 

 from the (Eningen beds. Fossil frogs have been 

 found in the coal formation of the Rhine, together 

 with the remains of certain fishes of the genus Leu- 

 ciscus, viz. L. macnirus and L. papyraceus. 



We pass from the toads to the pipas, or Pliiyna- 

 glosses pipajformes of Dumeril and Bibron, so called 

 from the total absence of the tongue ; in addition 

 to this, the internal auditory cavities communicate 

 with the mouth only by means of a single minute 

 opening in the middle of the posterior part of the 

 palate. Two genera are known, each containing 

 only one species, viz. Dactylethra and Pipa. 



2334.— The Surinam Toad 



{Pipa Americann, Laur.). Bufo dorsiger, Latr. 



In this strange reptile, the head is large, flattened, 

 and triangular, with the nostrils prolonged in the 

 form of a little cutaneous tube ; the eyes are very 

 minute and vertical, the eyelids reduced to a simple 

 rudiment incapable of closing over the eyes. There 

 are no teeth, either on the jaws or palate, nor are 

 parotid glands apparent. The anterior paws have 

 each four fingers, terminating in four star-like 

 points ; the hind limbs are short and thick, the feet 

 large, and the toes, five in number, completely 

 webbed. The body is broad and flat ; a little barbule 

 (barbillon) hangs on each side of the upper jaw, and 

 an ear-like appendage on each angle of the mouth. 

 The skin differs from that of all other Batracians, 

 being covered with minute hard granules ; amongst 

 which are scattered small conical tubercles of a horny 

 consistence. The male is distinguished by an enor- 

 mous larynx formed like a triangular box of bone, 

 within which are two movable pieces, the action of 

 which influences the intonation of the voice. 



The mode in which the eggs of this reptile are 

 hatched, and the circumstances connected with the 

 development of the young, are most extraordinary. 

 It would appear that as fast as the female deposits 

 her eggs, the male who attends her arranges them 

 on her broad back, to the number of fifty or upwards. 

 The contact of the skin with these egirs appears to 

 produce a sort of inflammation ; the skin of the back 

 swells, and becomes covered with pits or cells, 

 which enclose each a single egg, the surface of the 

 back resembling the closed cells of a honeycomb. 

 The female now betakes herself to the water, and in 

 these cells the eggs are not only hatched, but the 

 tadpoles undergo their metamorphosis, emerging 

 in a perfect condition, though very small, alter a 

 'apse of eighty-two days from the time in which the 



eggs were placed in their respective pits. M. Bi- 

 bron says, that the cells occupying the middle 

 portion of the back are, according to his own obser- 

 vations, those which are the flrst cleared of the 

 young, "bei-ause doubtless they are the first which 

 are formed, or the first occupied."* These pits are 

 only in the skin, and do not penetrate into the mus- 

 cular tissue beneath, nor communicate with the 

 interior of the body. Fig. 23:1:') shows the dispo- 

 sition of these cells and their situation on the skin, 

 which is thrown back so as to expose the muscles 

 below. The small separate figures are tadpoles in 

 different stages of development. 



The pipa, or Surinam toad, is of large size, of a 

 brown or olive colour above, whitish below ; it in- 

 htbits the marshes and swamps in the forests of 

 Guiana, Brazil, and other parts of South America. 

 According to Sebaund iMadame Merian, the negroes 

 eat its flesh. 



Before quitting the Banidaeor anurous Batracians, 

 we mnv allmle to a belief of ancient date which yet 

 prevaiTs, that young frogs and toads are occasionally 

 showered down with heavy rains, and that in great 

 abundance, so as to cover considerable spaces of 

 ground, where none had been previously observed ; 

 some have called in the aid of waterspouts, whirl- 

 winds, and similar causes, to account for their 

 elevation into the regions of air; and some have 

 even thought they were formed in the clouds, whence 

 they were precipitated. It has been generally in 

 August, and often alter a season of drought, that 

 these hordes of frogs have made their appearance. 

 Redi's explanation is doubtless the correct one : 

 these loads and frogs, he says, " do not appear until 

 it has rained for some time ; but these animals had 

 been hatched many days previously, or rather, had 

 quitted the water in which they were developed as 

 tadpoles, having undergone their complete trans- 

 formation. These little frogs then lay concealed in 

 the chinks of the earth, under stones and clods, 

 where in consequence of their lying ipotionless, and 

 often also on account of their dusky colour, they 

 escaped the eye." With this account M. Dumeril 

 agrees, observing that "the precise peiiod of the 

 year, the circumstance of rain always preceding the 

 appearance of these young frogs and toads, which 

 bear the signs of their recent transformation, and 

 generally the total absence of any violent commotion 

 of the wind, leave us in no doubt as to their origin. 

 We have ourselves observed the phenomenon in 

 question, once in I'icardy, near Amiens, and once 

 in the marshy meadows near Marbella in Spain : in 

 the latter instance, it was a host of little frogs that 

 made their appearance and covered our clothes, as 

 M. Desgennettes, now present at the Scientific 

 Meeting, may recollect." For further details we 

 refer to the 'Erpetologie Goncrale,' vol. viii. p. 223. 



We now pass to the Caudate Amphibia, les Uro- 

 dcles of MM. Dumeril and Bibron. 



Family SALAMANDRID7I': (TRITONS AND 

 NEWTS). 



233G. — A Group of British Water-Newts : 



a, the Common Water-Newt (Triton cristatus) ; b. 

 the Common Smooth Newt (Lissotriton punctatus) ; 



c, the Straight-lipped Water-Newt (iViton Bibronii) ; 



d, the Palmated Water-Newt (Lissotriton palmipes). 



2337. — The Common Water-Newt 

 (^Diion cristatus), male. 



2338. — The Common Water-Newt 

 (_Triton cristatus), female. 



2339.- The Common Smooth Newt 



(^Lissotriton punctattts). n, Male, 6, Female. 



Of the Water-Newts, four species inhabit the 

 ponds, ditches, and clear sluggish or standing waters 

 of our island. Lizard-like as these reptiles are in 

 appearance, they must not be confounded with the 

 lacertine group, with which LinnsBus, overlooking 

 their true characteristics, associated them under the 

 common term of Litcerta. Like the frog, the newts 

 begin their existence in a tadpole state, furnished 

 wijh tufted gills or branchifefor aquatic respiration, 

 which become ultimately lost, and are replaced by 

 true lungs adapted for a different medium. The 

 process of this structural change, which is essentially 

 the same as in the frog, we shall sketch as briefly as 

 possible consistent with clearness. 



On its first exclusion from the egg, the tadpole of 

 the water-newt exhibits on the sides of the neck the 

 lobes of the branchiae in a simple state, anterior to 

 which are a pair of holdere, by which the animal 

 attaches itself to objects in the water. Jn about 

 three weeks on the average, the anterior limbs have 

 become developed, with terminal feet, fourtoed and 

 distinct, the holders have disappeared, the branchial 



• It woiiltl seem that in females which have not as yet laid p^jl's, 

 these pit* are not to Ijc seen ; tliey begin to l)e developed when the 

 eg;(i are first arran)re<l on the bock, tlie skin of which, aHer the yonn;{ 

 hnvo quitted their tenement^ appearing honeycomlied all over. The 

 cells afterwards become ({rotlualiy obliterated. 



tufts have acquired a fringed character, and the eyes 

 have a.ssumed a definite outline; the little creature 

 now moves about with considerable rapulily, pro- 

 pelling itself through the water by the undtilatoiy 

 movements of its laterally flattened tail. In a short 

 time alter this, the anteiior limbs become more 

 perfect, the hind limbs begin to sprout, and the 

 uranchial tufts, three on each side, are much en- 

 larged and finely plumed. In a short time, the hind 

 limbs, and feet with five toes, are completely formed, 

 the boily has attained its nearly perfect figure, and 

 the branchia; have assumed a deeper colour and 

 firmer texture. The lungs are now rapidly develop- 

 ing, a change in the routine of the circulation is 

 gradually taking place, and the branchiae are be- 

 coming absorbed : towards the middle or close of 

 autumn they disappear, and air instead of waier 

 becomes the medium of respiration. A similar 

 transformation takss place in the tadpole of the 

 frog, with this addition, that the hind limbs fii-st 

 appear, and the compressed tail becomes absoibed 

 with the obliteration of the branchine. In the braii- 

 chisB of the tadpole of the newt and frog, when the 

 limbs have made some progress, the circulation of 

 the blood, when viewed through a good microsccp!-, 

 is calculated to excite the greatest admiration ; their 

 transparency is such as to [(ermit the currents of 

 globules rapidly coursing each ether to be distinctly 

 seen, as they ascend the arteries and return by the 

 veins to the aorta. We may here state that in the 

 tadpole condition of these animals, the circulation 

 of the blood resembles that of fishes.' The heart 

 consists of one auricle and one ventricle ; the auricle 

 receives the blood of the general system, and imme- 

 diately transmits it to the ventricle, which is mus- 

 t, cular; from this ventricle it is propelled into an 

 I arterial bulb (bulbus arteriosus), and thence tbrougli 

 i! a system of minute branchial arteries, and becomes 

 I subjected to the action of oxygen; from these arteries 

 \ it merges into the branchial veins or returning 

 ■ vessels, which ultimately unite to form a systematic 

 : aorta, without the intervention of a second ventricle. 

 |i As the branchisB become obliterated, the pulmonary 

 ! arteries develop, and the lungs begin to expand, till 

 ji at last the branchise are lost, and the heart and cii- 

 I culation have assumed new characters. The heart 

 now consists of two auricles and one ventricle : (ine 

 auricle of small size receives the arterialized blocd 

 from the lungs; the other, which is capacious, the 

 venous blood from the system, and both transmit 

 their contents through valvular doors into the com- 

 mon chamber of the ventricle. The fluid thus mixed 

 is sent through the bulbus arteriosus, and thence 

 partly to the general system and partly through the 

 pulmonary arteries, to undergo in the lungs the action 

 of oxygen. The development of the tadpole of 

 Triton cristatus, as observed by Rusconi, may be 

 easily understood by reference to the following illus- 

 trations. 



Fig. 2340 exhibits the evolution of the egg kept 

 on the leaf, as deposited by the female. The stages 

 are denoted by dates, from the beginning to the 

 time in which the young animal is about to emerge. 

 Each phase of the egg is shown of the natural size, 

 accompanied by a magnified view of the same 

 below. Fig. 2341 shows the tadpole on the day of 

 its leaving the egg. May Clh ; a, as magnified ana 

 seen from below ; h b, are the two eminences lormcd 

 by the globes of the eyes, and between them is a 

 slight depression which afterwards becomes th.' 

 mouth ; c, is the holder of the right side ; d, the 

 gills of the same side ; e, a rudiment of the fore 

 limbs of the same side ; f, the same animal in pro- 

 file ; g, the same seen from above. 

 I Fig. 2342 shows the development on the IStli of 

 May, twelve days alter exclusion ; a and b are mag- 

 nified representations. The fore limbs are loleiably 

 developed, and the branchiae are becoming finged. 

 Fig. 2343 represents the same animal, as it appears 

 on May 28th and June 12th ; a a, natural size ; b, 

 magnified. In the latter, the branchiae are beauti- 

 fully fringed, and the hinder limbs are in process of 

 development. Fig. 2344 shows the young newt in 

 its last stage, July ISlh, the branchiae now beginning 

 to shorten. This obliteration of the brancbiae goes 

 on for five or six days more, when they become re-- 

 duced to mere bud-liUe eminences ; the branchial 

 apertures have closed, the skeleton has become 

 firmer, teeth have appeared, and by the 27th of 

 July all traces of its former condition have entirely 

 passed away ; it has changed from the state of a fish_ 

 to that of a reptile. It wouUI appear that the - 

 changes dcscribeil are retarded or accelerated ac- 

 cording to the temperalure. In our i.^land the 

 process is more protracted than in the warmer parts 

 of the continent. 



The great water newt (Triton cristalus) attains 

 to the length of more than six inches, and is one of 

 the most atpiatic of its genus, residing almost con- 

 stantly in the water; we have, however, cajitured it 

 in meadows at the latter part of summer. Its biialit 

 orange-coloured abdomen, with distinct round s]).its 

 of black, together with its size, prevent the possibi- 



