ANNULOSA: INSECTA. 241 



to this rule, as seen in the Social Insects. In those organised 

 communities which are formed by Bees, Ants, and Termites, 

 by far the greater number of the individuals which compose 

 the colony are either undeveloped females, or are of no fully 

 developed sex. This is the case with the workers amongst 

 Bees, and the workers and soldiers amongst Ants and Termites. 

 And these sterile individuals, or " neuters," as they are com- 

 monly called, are not necessarily all alike in structure and 

 external appearance. Amongst the Bees all the neuters re- 

 semble one another, but amongst Ants and Termites they are 

 often divided into " castes " which have different functions to 

 perform in the general polity, and differ from one another 

 greatly in their characters. 



In all the above-mentioned insects the males are relieved 

 from the performance of any of the duties of life except that 

 of propagating the species ; and the females which are gene- 

 rally solitary in each community fulfil no other function save 

 that of laying eggs. All the other duties which are necessary 

 for the existence of the community are performed by the 

 workers, or neuters. 



The organs of the two sexes are in no case united in the 

 same individual, or, in other words, there are no hermaphro- 

 dite Insects. As has been noticed, however, before, asexual 

 reproduction is by no means unknown amongst the Insecta, 

 and the attendant phenomena are often of extreme interest. 

 (See Introduction.) 



CHAPTER XL. 



DIVISIONS OF INSECTA. 



THE class Insecta includes such an enormous number of species, 

 genera, and families, that it would be impossible to treat of 

 these satisfactorily otherwise than in a treatise especially de- 

 voted to Entomology. Here it will be sufficient to give 

 simply the differential characters of the different orders, draw- 

 ing attention occasionally to any of the more important points 

 in connection with any given family. 



As already said, the Insecta are divided into three divisions, 

 termed Ametabola, Hemimetabola, and Holometabola, according 

 as they attain the adult condition without passing through a 

 metamorphosis, or have an incomplete or complete metamor- 



VOL. I. Q 



