ARTHROPODA. 203' 



the insects have veined wings that look Uke those of 

 the Neuroptera ; but the two pairs are alike, and they 

 cannot be. folded. The White Ants, or Termites, he- 

 long to this sub-order. They are the Eomans of the 

 insect world ; they build cities and construct roads and 

 causeways as they march. They are polymorphous; 

 there are worker ants and soldier ants, which do not 

 develop sexual' organs; winged individuals, which are 

 the males, and in each ant-hill one female, or queen. 

 They eat most organic aubstances; and the part 

 they play in the scheme of nature is to clear away 

 the old vegetation of dense tropical forests. The 

 May-flies {Ephemeridce, i.e.. Day-flies) and Dragon- 

 flies belong to the same group. 



The true Neuropf.era, which have a complete meta- 

 morphosis, include the curious ant-lion of Southern 

 Europe, the larva of which, a grub-like creature, but 

 with hairy legs, digs a pit in sand, and lies in wait 

 at the bottom for ants to fall in ; and the Caddis- 

 flies [Phryganea), also called Spring-flies, whose larva, 

 the Caddis-worm, builds itself a protective tube of 

 sand and shells. 



The Hemiptera are sucking insects, some forms of 

 which have four wings, some two, and some none. 

 The lice are wingless forms (Aptera), while the Cochi- 

 neal insect and its allies have wings in the male. 

 The Aphidce, or plant-lice, are a. most interesting 

 group. They are peculiar in exhibiting partheno- 

 genesis, or asexual reproduction. The males and 

 females are produced mostly in the autumn, and the 



