60 THE VITAL FUNCTIONS. 



feast upon the juices which they extract from 

 flowers, or other parts of plants; others, again, 

 derive their principal nourishment from the hard 

 fibres of the bark or wood. 



Still more general is the consumption of animal 

 matter by various animals. Every class has 

 its carnivorous tribes, which consume living prey 

 of every denomination ; some being formed to 

 devour the flesh of the larger species, whether 

 quadrupeds, birds, or fish ; others feeding on 

 reptiles or moUusca, and some satisfying their 

 appetite with insects alone. The habits of the 

 more diminutive tribes are not less predatory 

 and voracious than those of the larger quad- 

 rupeds ; for the spiders on the land, and the 

 Crustacea in the sea, are but representatives of 

 the lions and tigers of the forest, displaying an 

 equally ferocious and insatiable rapacity. Other 

 families, again, generally of still smaller size, are 

 designed for a parasitic existence, their organs 

 being fitted only for imbibing the blood or juices 

 of other animals. 



No sooner is the signal given, on the death of 

 any large animal, than mvdtitudes of every class 

 hasten to the spot, eager to partake of the repast 

 which nature has prepared. If the carcass be 

 not rapidly devoured by rapacious birds, or car- 

 nivorous quadrupeds, it never fails to be soon 

 attacked by swarms of insects, which speedily 

 consume its softer textures, leaving only the 



