BATRACHLVNS OF SOUTHEEN INDIA. 



GENERAL NOTES. 



The Batrachia are placed, according to Huxley's system of classifica- 

 tiou, with the Fishes {Fisceti) among the Ichthyopsida, one of the three 

 groups ^ of Vertebrata. 



They may be defined as cold-blooded (poikilothermic) vertebrate 

 animals, the majority of which have a pair of lungs situated below 

 the digestive tract, which breathe by means of gills during some or 

 the entire period of their existence, have three chambers (two auricles 

 and a ventricle) to the heart, and two or no occij)ital condyles. Their 

 limbs, if present, have not more than five fingers developed, and if, as is 

 rare, they possess dorsal fins, these are merely folds of the integuments 

 without those supporting cartilaginous rays which are found in fishes. 



Recent Batrachians belong to the three following orders : — 



1. Ecaudata, Anura, or tailless Batrachians ; 



2. Cmidata,' Urodela, or tailed Batrachians ; 



3. Apoda, Gymnophiona, limbless Batrachians or Coecilians. 



Of these three orders, only two, the Ecaudata and Apoda, have been 

 recorded from Southern India, the former including the frogs and 

 toads, and the latter the worm -like Coecilians. 



The skin of Batrachians is, as a rule, naked, though the Coecilians 

 have thick cutaneous rings, imbedded in which are small scales. The 

 cutaneous glands of many Batrachians secrete an acrid milky juice, 

 which not only serves to keep the skin moist, but also acts as an 

 irritant,^ and serves as a means of self-defence. In some Batrachians, 

 e.g., the common South Indian toad {Bufo melanostictas), the glands 

 on the side of the neck form two prominent masses, and are called 

 the parotoids. In addition to its secretory function, the skin, which 

 is provided with an abundant blood-supply, is also an important 

 accessory organ of respiration, and it has been shown by experiment 

 that a frog can live for a long time after extirpation of its lungs by 

 means of its cutaneous respiration. In some Batrachians the highly 

 vascular swimming tail, lying against the egg-membrane, may serve 

 as a larval respu'atory organ. 



In most of the Batrachians the ova are impregnated and hatched 

 outside the body, and the young undergo a series of metamorphoses. 

 These changes or metamorphoses are partially represented as they occur 



1 IcHTHYOPSiDi, Sauropsida {EcptiHa and Arcs), and Mammalia. 



'^ Writing concerning the geographical distribution of the Batrachia in the Indian 

 region, Boulenger says: "Two forms of C'audata occur, viz., Ti/lofrUon, m Ymman and 

 the Himalayas, and a species of the otherwise entirely North American genus Ambhjstoma, 

 •which has been found in the mountains of Laos. These forms, however, cannot be 

 considered to be characteristic of the Indian region, but should be regarded as immigrants 

 from the northern zone ; and, in fact, they seem to be limited to such altitudes as compen- 

 sate the difference of latitude." Cat. Batr. Grad., 1882, p. 112. 



' Handling the common English toad is said to be frequently succeeded by inflam- 

 mation of the eye-lid. 



