116 



HABITS AND INSTINCTS OP ANIMALS. CHAP. IV. 



fish crawling upon dry land, has naturally excited the 

 superstitious Hindoos to believe that they fall from 

 heaven. The Perca scandens (fig. 35.), which be- 



35 



longs to the same natural tribe as the last (Spiro- 

 branchidfs Sw.), quits the water, and ascends the 

 roots and branches of the mangrove trees, an effort it 

 accomplishes by using its ventral fins as little feet : it 

 is not clear, however, what purpose it has particularly 

 in view, in thus quitting an element it is obviously de- 

 signed to inhabit; yet, that these terrestrial expe. 

 ditions are perfectly natural to them, is proved by the 

 fact of the whole of this tribe, having a particular or- 

 ganisation. By this, a provision is made for retaining 

 a sufficient quantity of water in the gills, in order to 

 keep them in a state of moisture while the fish is out 

 of water. 



(136.) The progressive motion of frogs and toads, 

 in their adult state, is by leaping ; and the bull frog 

 of Carolina, particularly mentioned by Catesby, is very 

 remarkable for the length and rapidity of these springs. 

 The tadpole of these two families are well known to 

 resemble fish externally, and to live, like them, entirely 

 in the water : they are much more active in this state ; 

 constantly moving their little tails with a rapid vibratory 

 motion, and swimming in shoals, on a sunny day, round 

 the ponds which have been then birthplace. 



(137.) But it is among the class of INSECTS that we 

 find concentrated all those various motions that are but 



