THE BATRACHIANS AND THE REPTILES OF INDIANA. 



On the part of people who have not made a scientific study of aniiiials 

 no distinction is made between the group of creatures here called Batra- 

 ehians aud that group called Reptiles. The amphiuma and the snakes, 

 the salamanders and the lizards, the common toad and the turtles are all 

 called "reptiles." Nor is this strange when we consider how closely 

 members of both groups resemble one another in outward form and in 

 habits. It is indeed only recently that zoologists, who endeavor to found 

 their systems on more important differences than appear on the outside, 

 have agreed to regard the frogs, salamanders, and newts, as fundament- 

 ally different from the lizards, turtles, and snakes. In reality, the ba- 

 trachians are more closely related to the fishes than to the reptiles, while 

 the latter are more nearly akin to the birds The batrachians form a 

 class standing intermediate between the class of fishes and the class of 

 reptiles. 



Nevertheless, since zoologists have almost universally associated the 

 two classes in their works, and since people do not usually distinguish 

 the one kind of animals from the other, they are here described together. 



The batrachians differ from the reptiles in several important respects. 

 The skin of the former is usually smooth and moist, sometimes raised up 

 into warts, as in the toads, but never disposed in overlapping scales or 

 regular plates. Scales and plates, such as are seen in the lizards and 

 snakes, and tortoises, are almost universal among the reptiles No In- 

 diana reptile is without such a covering, except our soft-shelled turtles. 

 The life-history of the members of the two groups is also widely diflferent. 

 The batrachians almost always lay their eggs in the water, and the young 

 pass their early days there as tadpoles. They respire by means of gills 

 until the time of their metamorphosis approaches, when lungs are de- 

 veloped, the gills are absorbed, and the animal leaves the water and 

 lives to a greater or less extent on the land. Reptiles, on the contrary, 

 lay their eggs on land, the young are hatched with the form of the 

 adults, and they never have gills. A few batrachians retain their gills 

 life-long, breathing both by means of these and their lungs. Other dif- 

 ferences exist, but since their determination would require dissections, 

 they are not thought suitable for consideration in a work of this kind. 



