DISTRIBUTION OF ORGANISMS. 175 



cepting a horny sheath in a few species. They are also devoid 

 of ribs, or present at the most rudiments of such bones. 



The ungainly form of the toad has caused it to be no fa- 

 vourite with our race, and given rise to many reports against 

 it, particularly one respecting its venomous qualities, which is 

 quite false. A French naturalist remarks that, if we could 

 behold the frog without prejudice, we should see in it an 

 animal uniting an elegant form with light and slender limbs, 

 adorning the banks of the rivulet with its pleasing colours 

 (only less variable in some species than those of the chameleon), 

 and animating the scene with its light and lively gambols. 

 The croaking noise of the frog is proverbial ; this is changed 

 in the love season to a soft and plaintive note. A modern 

 writer says, " A traveller towards the desert shores of the 

 Caspian and the Volga would imagine that he heard of a sud- 

 den, in the evening, a joyous assembly of men and women 

 laughing very heartily. He approaches ; the inextinguishable 

 laughter redoubles among the rocks, and, to his astonishment, 

 he finds that it proceeds from an assembly of enormous black 

 toads, celebrating their nuptial rites." ( TT ) 



Although the frogs and toads are now, generally speaking, 

 small animals, we must recollect that such has not always been 

 the case. The Labyrinthodon of the Warwick Sandstone, an 

 animal allied to the frog, is believed to have been as large as 

 a good-sized hog. It may at the same time be remarked that, 

 if this was the utmost size attained by batrachia in the era of the 

 secondary formation, they were then, as now, relatively much 

 smaller than the saurian order, of which several reached the 

 length of thirty, forty, and even, it is believed, seventy feet. 



A second division of batrachia is composed of animals of 

 which the salamander is the type ; hence called Salamandridce. 

 In them, the tail is largely developed : in other respects, as in 

 their reproductive history, they resemble the preceding divi- 

 sion, the water newts being analogous to the frogs, and the 

 land salamanders to the toads. They also resemble the ranidae 

 in habits ; but one remarkable species, the Menopoma of the 

 Ohio and Alleghany rivers, which reaches two feet in length, 



