294 PERIPATUS, MYR10P0DS, AND INSECTS. 



from the secretion of the colleterial glands. Each egg is 

 enclosed in an oval shell, in which there are several little 

 holes (micropyles), through one of which a spermatozoon 

 enters. Spermatozoa, from the store within the spermatheca, 

 are included in the egg-capsule. The development is 

 similar to that of other insects, and it has already been 

 mentioned that there is no metamorphosis. 



At an early stage in development some . cells associated with the 

 mesoderm are set apart as reproductive cells, and originally these have 

 a segmental arrangement as in Annelids.; at a later stage other meso- 

 derm cells join these, some forming ova, others epithelial cells around the 

 latter. The distinction between truly reproductive cells and associated 

 epithelial cells, which is said to be late of appearing in some of the 

 higher insects, is established at a very early stage in the cockroach. 



Second Type of Insects. — The British Hive-Bee 

 (Apis mellifica). 



This is a much more highly specialised type than the 

 cockroach. It belongs to the order Hymenoptera. 



Habits. — The Hive-Bee (Apis mellifica) is a native of 

 this country, and is the species most commonly found 

 domesticated. It is the only British representative of the 

 genus Apis, and exhibits, in its most fully-developed form, 

 the social life which is foreshadowed among the Humble- 

 Bees. As a consequence of this social life, there is much 

 division of labour, which expresses itself alike in habit and 

 in structure. The males (drones) take no part in the 

 work of the colony, and are wholly reproductive; the 

 females include the queen-bees and the workers. In the 

 workers, which perform all the work of the hive, the 

 reproductive organs are normally abortive and functionless. 

 In the queens, of which there is but one adult to each hive, 

 the enormous development of the reproductive organs seems 

 to act as a check upon the brain and other organs, which 

 are less developed than in the workers. The workers are 

 further divisible into nurses, which are young and do not 

 leave the hive, being occupied with the care of the larvae, 

 and the older foraging bees which gather food for the whole 

 colony. 



In considering the relation between the life of the Hive- 

 Bee and that of many allied forms (Bombus, etc.), it is 



