288 PERIPATUS, MYRIOPODS, AND INSECTS. 



there is a dorsal and ventral row on each side. In P. novce zealandice 

 the tracheae are said to be branched. 



The Excretory System. A pair of nephridia lie in each segment. 

 Each consists of an internal terminal funnel, a looped canal, and a wide 

 vesicle which opens near the base of each leg. They are not very differ- 

 ent from those of many Annelids, but their occurrence in a Tracheate 

 is remarkable. The salivary glands and the genital ducts are probably 

 modified nephridia. It may be noted, too, that the same is perhaps 

 true of the " coxal glands " of Limulus and of the antennary glands of 

 Crustaceans. 



Crural or Coxal Glands lie in the legs and open to the exterior. Their 

 meaning is uncertain, their occurrence is variable. Thus in P. edwardsii 

 they occur in the males only, in P. capensis they are present in both 

 sexes. In the male of P. capensis the last pair are very long (a.g., 

 Fig. 93). The large mucus glands, which pour forth slime from the oral 

 papillae, are regarded as modified coxal glands. 



Reproductive System. (a) Female (of P. edwardsii]. From the two 

 bvaries, which are surrounded by one connective tissue sheath, the eggs 



F.I 



F.2 



FIG. 93. Dissection of Peripatus capensis. 

 (After BALFOUR.) 



at., Antennae; or,p., oral papillae; e.g., cerebral ganglia ; sl.d., 

 duct of slime gland (sl.g.) ; s.o.8, segmental organ or nephridium 

 eighth ; v.c., ventral nerve connected by transverse commissures (co.) 

 with its fellow; v^.g., last crural gland; s.o.i?, seventeenth neph- 

 ridium; -.0., genital aperture; A, anus; p.d.c., posterior com- 

 missure ; F.if, seventeenth appendage : a.g., last crural gland; 

 F.I, F.2, first and second legs ; oe.co., oesophageal nerve commis- 

 sure. 



pass by two long ducts leading to a common terminal vagina opening 

 between the second last legs. These ducts are for the most part uteri, 

 but on what may be called the oviduct portions adjoining the ovaries, 

 there are two pairs of pouches (a) a pair of receptacula seminis (for 

 storing the spermatozoa received during copulation), and a pair of 

 receptacula ovorum for storing fertilised eggs. 



The eggs are hatched in the uteri, and all stages are there to be found 

 in regular order. The young embryos seem to be connected to the wall 



