TRACHEATA 401 



and owing to the way the metasoma is usually carried, over 

 the head, it can readily be injected into any prey which has 

 been caught and held by the pedipalpi. 



The generative glands, like those of Lhnulus, consist of a 

 network of tubules; these are hollow, and the cells lining 

 their lumen give rise to the reproductive cells. The testes 

 consist of two pairs of longitudinal tubules united by cross 

 branches, on each side of the body ; the efferent duct leads to 

 the external opening on the first mesosomatic somite ; its distal 

 end is modified to form an intromittent organ, and it bears 

 accessory glands. 



The ovary is single, and consists of three longitudinal 

 tubules united by transverse ducts ; it lies ventral to the 

 liver, and is to some extent embedded in that organ. The 

 ovary is situated in the mesosoma, and the oviducts run 

 forward, one on each side, to open upon the genital operculum. 

 The ova are formed by the growth of cells lining the tubules, 

 and they project from the surface in the form of follicles. 

 They are fertilised in situ, at any rate, in 'One species. After 

 going through the early stages of segmentation, they pass into 

 the oviduct, and there complete their developement. The young 

 are born in a condition resembling their parents, the scorpion 

 being viviparous. 



Class II. Pseudoscorpionida. 



Chakacteeistics. — The abdomen is not divided into meso- 

 and meta-soma, hut is hroad and fiat, and consists of ten or 

 eleven somites ; the animals are all minute; they breathe by 

 tracheae ; the pedipalpi are chelate. 



In many respects the Pseudoscorpions resemble minute 

 scorpions, but their abdomen is not produced iato a tail, nor 

 does it terminate in a poison gland. They breathe by 

 tracheae, which open externally by two pairs of stigmata 

 situated in the third and fourth abdominal somites. Like 

 spiders, they are provided with spinning glands, which lie 

 partly above the liver in the prosoma, and which open at 

 the tip of the moveable joint of the chelicerae. 



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