The pubis remains cartilaginous much longer than the ischium. with which it is united by a suture which makes a cross with the symphysis, and in front of this symphysis is a cartilage in the form of a Y in the muscles, which recalls to the observer the marsupial bones of the Opossnins. The upper head of the femur is oval ; at the internal face of the neck, there is a very pointed apophysia, ocoupying the place of a trochanter : the lower head is widened and flattened from before backwards. There are two bones in the log. The tibia, which is very stout upwards, has in front a ridge, which detaches itself from the upper part of the bone in the form of a slender stem, resembling the vestige of a fibula discernible in various Rodents, but this does not prevent the development of a true fibula as large as the tibia, and which descends a little lower. There are 9 tarsal bones, all flat and disposed in a pavement-like order: the lower rank has 5 for the five metatarsal bones ; the four others consist of one small (the tibial) at the internal border, one great (the fibular) at the external border, an oblong one between them, placed obliquely and answering to the tibia and fibula, and one square in the middle of all the others. envier found but one phalanx on the first finger, two on the second, three on the third and fourth, and two on the last.
Reproduction of Parts.—Tho power of reproducing excised or injured parts has been observed in no family among the reptiles more carefully than in the Taikd .A mphibia. Plateretti, Spallanzani, Murray, and others have recorded their observations with respect to this power; and Bonnet particularly has given most accurate descrip tions and figures of his careful experiments. The arms or thighs of Tritons amputated sometimes on one side, sometimes on the other, or both on the same side, were constantly reproduced, and the toed were again gradually formed and endowed with motion. The tail, too, cut off at various points, was renewed, pushing out by little and little from the amputated base. lu one case the same limb was reproduced four times consecutively in the same animal. Bonnet found that this reproduction was favoured by boat and retarded by cold. He observed that the parts of excised limbs were often reproduced with nimarkable alterations, either of defect or excels ; the deficiency or exuberance of certain parts taking upon themselves very singular forms. In many species of Tritons the long bones of the limbs detached from their principal articulation, and remaining suspended by some points which still caused them to adhere to the flesh, were found completely consolidated in a few days. The moat extraor dinary observation was that consequent on the total extirpation of the eye, which was entirely reproduced and perfectly organised at the end of a year. Dufsy has recorded their faculty of remaining frozen up
in ice for a long period without perishing.
Their tenacity of life was strongly shown in an experiment made by M. Dum6ril. Three-fourths of the head of a Triton marmoratua was removed with a pair of scissors. The mutilated animal was placed by itself at the bottom of a large glass vessel in fresh water about half an inch deep, and which was carefully renewed at least once a-day. The animal, although deprived of the four principal senses, without nostrils, without eyes and ears, and without a tongue, continued to live and move slowly. Its only communication with externals was carried on by touch alone. 3L Dum6ril relates that it was evidently conscious of existence, and walked slowly and cautiously. It raised the stump of its neck towards the surface of the water, and during the first days was seen making efforts to breathe. In less than three months reproduction and cicatrisation had so done their work that there remained no aperture for the lungs, or for food. At the end of three months, M. Dum6ril was compelled to leave it to tho care of another during an absence, and it died, in all probability, as he observes, from want of attention on the part of the person who undertook the care of it. This specimen is now preserved in the Paris Museum, and exhibits, as M. Dum6ril remarks, the singular fact of an animal having lived without a head; and a proof of the possibility and necessity, even in the Batra ehians, of a sort of respiration by means of the skin. In this animal 3L Dumeril states that respiration was certainly thus carried on for three months, although the stump of the amputated part presented a cicatrice, the smooth surface of which proved, even when examined by a magnifying glass, that there was a complete obtura tion of the oesophagus and larynx.
Dr. Von Siebold has also recorded his observations on the reproduction of wounded or lost parts in the Triton niger.
The following are some of the more remarkable genera belonging to the Tailed Am phibia :— Protonopsis.
Head flat, broad ; two con centric rows of teeth (the inner row palatine) in the upper jaw, and a single row only in the lower jaw; tongue free in front; operculiun situated about half way between the posterior edge of the rictus of the mouth and the fore-leg; throe op ercular cartilages, between the posterior, two of which four the aperture; feet fimbriatcd on their outer edge; toes four on the anterior feet, and five on the posterior; of the latter the fourth and fifth are webbed and without claws.