434 



AMPHIBIA. 



the water to pass a considerable portion of its time on land, although nearly 

 always returning to its original element for the purpose of breeding. It has 

 been said that the external gills usually form two pairs, but it should be 

 added that, in some instances, these are increased to three, while in one case 

 they are reduced to a solitary pair. 



As regards their mode of life, amphibians are especially characterised by 

 their partiality for moisture, some passing the whole of their time in the 

 water, while none are found in absolutely desert districts. To their soft 

 sensitive skins moisture is, indeed, an absolute necessity ; and it seems that 

 they imbibe such moisture as they require through the skin. In countries 

 where one season of the year is especially dry, terrestrial amphibians are 

 consequently compelled to undergo a period of more or less complete torpor. 

 To a certain extent this is the case even in Britain, where a sudden shower 

 after a dry spell brings out numerous frogs and toads at the commencement 

 of evening in gardens where not one had been visible previously. In some 

 parts of Argentina the effect of a shower after a drought is much more 

 startling. There a garden may appear for weeks or months absolutely devoid 

 of amphibian life, but after a single shower it will appear literally alive with 

 huge frogs and toads of various kinds. Probably all the terrestrial amphibians 

 are essentially nocturnal creatures, and, indeed, their skins soon become 

 parched and withered by exposure to sunlight. Few objects are more pitiable 

 than a belated frog or toad attempting to cross a dusty high-road in the full 

 glare of the summer sun. Cloudy or wet days will, however, generally tempt 

 these creatures from their hiding-places. Although the tailed forms are 

 entirely or mainly silent creatures, frogs and toads during the breeding season 

 utter their well-known croaking cries, and in moist tropical and subtropical 

 countries life is rendered at times almost unbearable by their nocturnal 

 choruses. In the breeding season frogs and toads become exceedingly bold, 

 and they may be seen sitting within a few feet of the spectator, alternately 

 dilating and contracting their capacious throats, as they give vent to their 

 discordant cries. In order to make their sounds more intense, the males of 

 many kinds are furnished with large sacs projecting on either side of the 

 throat, which can be dilated till they resemble miniature balloons. Most 

 members of the class subsist chiefly or entirely on insects and other small 

 invertebrates, but some of the aquatic kinds consume fish, and some of the 

 larger toads and frogs will readily attack not only other reptiles, but even the 

 smaller birds and mammals. Thus a newspaper correspondent, writing from 

 Nagpur, in India, observes that in the garden adjoining his house was a small 

 pond, which was the home of a huge kind of frog. One afternoon he heard 

 a myna making a great noise, and screaming as though it had been caught by 

 some creature, so he went down the garden to ascertain what was the matter, 

 and was just in time to see the bird disappearing down a big frog's throat. 

 There were only a few feathers loft, and the bird had been swallowed feathers 

 and all. Now the common myna is quite as large as our English starling, and 

 the frog certainly looked as though he had dined, so he was left in peace to 

 enjoy his meal. On another occasion a big rat appeared in the house, and 

 was being chased by himself and servants from room to room, when it dashed 

 through a disused bathroom. A large frog which happened to be there made 

 a most determined rush, but missed tlie rat, which disappeared down the 

 waste water-pipe. 



In conformity witli their fondness for warmth and moisture, amphibians 

 are most abundant in the tropical and sub-tropical portions of the globe, 



