ANNULOSA : INSECTA. 221 



upon its peace, for which purpose the mandibles are greatly 

 developed. 



It may well be admitted, that in such organised communities 

 as those of the Termites, we have the highest development of 

 In sect- life yet known to us. The principle of the division of 

 labour is carried out to its fullest extent much further, 

 indeed, than is possible amongst human beings since the 

 perfection of the greater number of the individuals which 

 compose the community as organisms is sacrificed in order 

 to secure the fulfilment of the duties which are necessary for 

 the existence and welfare of the whole. Even the task of per- 

 petuating the species and of giving origin to fresh colonies is 

 entirely left to one class of the community, the defence and 

 protection of which is the special object and care of the re- 

 mainder. No higher development could well be imagined 

 amongst creatures devoid of the higher psychical endowments, 

 and it is worthy of note that at least three distinct and inde- 

 pendent families of Insects have attained to this stage, namely, 

 the Termites, the Bees, and the true Ants. 



SUB-CLASS III. HOLOMETABOLA. Metamorphosis complete ; the 

 larva, pupa, and imago differing greatly from one another in 

 external appearance. The larva vermiform, and the pupa 

 quiescent. 



ORDER VII. APHANIPTERA. Wings rudimentary, in the form 

 of plates, situated on the mesothorax and metathorax. Mouth 

 suctorial. Metamorphosis complete. 



This order comprises the Fleas (Pulicidce), most of which 

 are parasitic upon different animals. The larva of the com- 





Fig. 66. Diptera. 1. Tabanus cinctus, the belted Breeze-fly. 2. The organs 

 of the mouth magnified. 



mon Flea is an apodal grub, which in about twelve days spins 

 a cocoon for itself, and becomes a quiescent pupa, from which 

 the imago emerges in about a fortnight more. 



ORDER VIII. DIPTERA. The anterior pair of wings alone 

 developed ; the posterior pair of wings rudimentary, repre- 



