Marvels ot the Universe 



i8i 



Let it be said at once that the Diving Beetle is carnivorous and 



at home in a roonij" aquarium 

 that it possesses a voracious appetite. It is, indeed, a veritable fresh-water shark, and the dispatch 

 ^\'ith which it accounts for small fishes, newts, frogs, tadpoles, grubs, and other under-water 

 dwellers has earned for it the equivocal title of " water devil." 



Being an insect, the Diving Beetle is furnished with six legs. It has also four wings ; but while 

 the lower pair are well adapted for sustained flight, the upper pair consist of hard plates which 

 cover and protect the more delicate functional wings when the latter are not in use 



A beetle is planned quite differently from a backboned animal, such as a rabbit or a fish. It 

 possesses no internal skeleton for the attachment of its muscles. Instead, its skin is thoroughly 

 permeated with a peculiar substance called chitin, which is remarkably hard and durable, well 

 calculated to resist the weather, and to sustain the wear and tear of an active life. Thus, for 

 practical purposes, we may regard the beetle as living within a suit of strong, light armour, to the 

 inner walls of which its muscles are attached. This suit of armour is always divided into three 

 compartments. The first encases the head, the second — from which spring the six legs and the 

 wings — protects the " chest," while the third envelops the hind body. 



This type of structure is common to all beetles. But in the case of the Diving Beetle we shall 

 notice certain modifications which fit the creature in a marvellous manner for its aquatic life. 



The Diving Beetle is not a mere surface swimmer. It is specially designed for under-water 

 voyages. Its body is like a submarine — oval, somewhat flattened, having a highly-polished surface, 

 and with its several parts so closely adjusted as to present practically a continuous outhne. This 

 smoothly elliptical contour and polished surface serve to lessen friction, which, as every naval 

 architect wall testify, is so serious a hindrance to speed. 



YOUNG CAIMANS EMERGING FROM THE EGG, 



These eggs are about the size of those of a goose, though more elongated in shape. The shell is quite hard, but the young 

 Caiman is armed with a ipecial temporary tooth with which he can break down his prison walls. 



