THE ANIMAL KINGDOM. 345 



daring flight some of the wading birds cleave their way 

 through the clouds and sweep a whole hemisphere, a little 

 family of humming-birds have only a rose-bush for their 

 universe. Like an elegant vase ornamented with lichens, 

 the Colibri's downy nest of cotton is balanced on the ex- 

 tremity of the most slender branches of the plant, whilst 

 these aerial diamonds make prey of the insects which the 

 flowers attract, or drink the pearls of dew which their 

 petals distil. This is, for instance, the life of the Typhcenu 

 Duponti. 



In the same maimer the humming-birds robed in 

 changing green, the "emeralds of Brazil" (Chlorostilbon 

 prasimis), as they are commonly called, set up their family 

 nests upon the creepers, from the vicinity of which they 

 scarcely move. 



CHAPTEE III. 



MIGRATIONS OF REPTILES AND FISHES. — SHOWERS OF FROGS. 



Reptiles scarcely ever carry out migrations on such a 

 scale as to astonish one, either by the number of travellers 

 or by the space over which they extend, but there is one 

 fact in their history which has given rise to long debates, 

 and that is the shoivers of toads and frogs, which in reality 

 mean compulsory migrations. 



Mention is made of these in very remote times, but it 

 was geherally believed that the assertions of the authors 

 who related them were inventions. Modern observations 

 have at last demonstrated the actual existence of this 



