48 



the tail. At the same time the black callosities appear on the hind legs^ 

 In their courtship the males are very active and very ostentatious. When 

 success is won, they seize the female around the body and remain thus for 

 an hour or more. Prof. Gage finds that the sexes pair in the fall as well 

 as in the spring. 



The outer skin is frequently shed. It is pushed back from the head by 

 rubbing against objects ; sometimes the hands ai'e employed to efiect this 

 purpose. The process of moulting occupies about an hour and a half. 

 Samuel Lookwood (22, x, 11) has seen it free itself of the cuticle while 

 under the water ; immediately the little thing turned around and swallowed 

 the whole skin. Prof. Gage has seen the terrestrial form pull the 

 exuvium off the end of the tail and swallow it. It is also interesting that 

 the Newt can utter a faint shrill cry. The tail is extremely prehensile, 

 and may be employed to suspend the animal for some time. It has been 

 observed by Prof. Gage that during the aquatic stages the epithelium of 

 the mouth is of the non-ciliated variety, while during the 7niniatus stage 

 the epithelium is ciliated. Furthermore, the adults, while living in the 

 water enjoy a form of aquatic respiration, water being regularly taken 

 into the mouth and again expelled. 



Order SALIEiN"TIA. 



Batrachia having a frog-like, or toad-like form. All four limbs present, 

 the hinder greatly developed and fitted for leaping. Proximal elements 

 of tarsus elongated, so as to form an additional limb segment. Vertebrae 

 in front of the sacrum not exceeding nine. Ribs rarely present. No 

 tail in the adult state. A tympanic cavity present. 



This order includes the frogs and toads. With rare exceptions, the 

 eggs are laid, fertilized, and hatched in the water. The young are familiar 

 to all as tadpoles. These breathe for a short period by means of external 

 gills, and for a longer time by internal gills. The intestines are long, the 

 mouth furnished with horny sheaths, and the lips with several rows of 

 horny teeth. By means of these, the little tadpoles are enabled to sup- 

 port themselves by scraping off the minute vegetable matter which covers^ 

 objects in the water. As growth progresses, the limbs develop ; the fore 

 limbs, however, are for a long time concealed beneath the skin, and when 

 they break through, they appear to be produced suddenly. As the period 

 of metamorphosis approaches, the horny jaws and denticles are shed, the 

 mouth enlarges, the tongue appears, the intestine shortens, the tail is 

 absorbed, respiration by the lungs prevails, the gills disappear, and the 

 tadpole leaves the water and becomes a frog. 



All regions of the world, except the very coldest and the very driest, 

 furnish representatives of this Order. Altogether there are about 800' 



