14 BRITISH ArHIDES. 



but little convoluted in the apterous larva, but in the 

 winged female it is bent into a loop at the lower part 

 of the abdominal cavity before it descends into the 

 rectum. 



The viviparous females develop twenty or more 

 embryos, which, at the breeding time, differ greatly 

 in size, according to their maturity. These embryos 

 show red eyes, each compounded of three or four 

 simple lenses. These foetal eyes are quite as large 

 as those borne by the full-grown insects ; thus showing 

 that an arrest of growth as to the eyes occurs during the 

 larval states. It is only after the insect has assumed 

 wings that the complex eye with its ocellus and the 

 stemmata are fully developed. 



Behind the three lenses of the apterous female I 

 have more than once discovered a mass of red rods 

 and cones radiating from a centre. These bodies con- 

 stitute the sensitive terminations of the fibres in com- 

 munication with the optic nerve. 



The nectaries of the winged female, although very 

 short, have large expanded mouths and long internal 

 tubes, which decrease in diameter, and finally end in 

 transparent ducts. These apparently do not anas- 

 tomose with any viscus, but seem lost in the general 

 fluids of the body. The ducts are directed towards 

 the anal ring ; but whether they have any function 

 analogous to ureters it is not easy at all to decide. 

 Similar ducts may be noted in other genera as well as 

 in Thelaxes. 



The reproductive organs of the oviparous female are 

 well suited for dissection. They will be described in 

 the anatomical chapters at the conclusion of this 

 volume. 



