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PHYLUM ARTHROPODA 



Reproductive System 



Sixteen ova, one from each ovarian tube, are usually 

 enclosed within each egg-capsule. The latter is formed 

 from the partly calcareous secretion of the arborescent 

 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. 



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 



