2l6 



FIRST LESSONS IN ZOOLOGY 



the adults cannot breathe under water. The toads 

 and frogs are closel)' related, and have about the same 

 life-history and habits, except that the fully-grown 

 toads live on land instead of in and about ponds. In 

 structure toads differ from frogs in having no teeth. 

 There arc onl)- a few toad species in North America, 

 but one of these is very abundant and widespread. It 

 appears in t\vo or three varieties, the common toad of 

 the Southern States differing in several particulars from 

 that of the Northern. The toad is a familiar inhab- 

 itant of gardens, and does much good by feeding on 

 noxious insects. It is most active at twilight. Its eggs 

 arc laid in a single line in the center of a long, slender, 

 gelatinous string or rope, which is nearly always tangled 



Fig. i75.--'riie rtmorn or cliii^r fij],, Rdiiioropsis lirachyphra; by means of 

 til'.- curious sucker on lop of the head this fish clings to sharks and is 

 thus carried swiftly for long distances. (After Goode.) 



and wound round some water-plant or stick near the shore 

 on the bottom of a jsond. The eggs are jet black, and 

 when freshly laid arc nearly spherical. At the time of 

 the egg-laying the toads croak or call, making a sort of 

 \vhistling sound, and at the same time pronouncing deep 

 in the throat " bu-rr-r-r-r. " The toad does not open 

 its miouth AN'hen croaking, but expands a large sac or 

 resonator in its throat. The toad tadpoles are blacker 

 than those of frogs or salamanders, and undergo their 

 metamorphosis while of smaller size than those of frogs. 

 When the)' leave the A\'ater they travel for long distances, 

 ho}:)ping along so vigorously that in a few da3's they mav 

 be as far as a mile from the pond where they were 



