510 Mr. C. L. Witliycombe's Notes on 



The testes lie dorsally in the hind part of the abdomen. 

 They may be separate, or enveloped in a common yellow 

 scrotum. Vasa efferentia lead ventrally, one on each side 

 of the alimentary canal to the vesicnlae seminales, which 

 are large. Ventrally a ductus ejaculatorius leaves these 

 and runs to the " penis." 



Ovaries are meroistic (poly trophic), each of eight to twelve 

 egg-tubes, the tubes being attached longitudinally in pairs. 

 Accessory glands are present at the base of each oviduct, 

 large in Nothochrysa. Cement glands are paired in the 

 female, but generally only one is fully developed, the other 

 being small. They run into the vagina, and may secrete 

 silk in Sisyra, cement in Osmylus and Hemerobms, and egg- 

 stalks (= cement) in Chrysopa. 



In working out the anatomy, resort has been had largely 

 to micro-dissections under water, in addition to microtome 

 sections. The most careful work from sections alone has 

 in the past led to misinterpretations, and especially is this 

 so upon such points as the number of Malpighian tubes. 

 Many contradictory statements have been made. Anthony 

 (1 ) in some excellent work on Sisyra states that the number 

 of Malpighian tubes is five, of which three are attached 

 distally and two are free. My dissections have generally 

 revealed eight Malpighian tubes in Sisyra, six being looped 

 as usual, but it must be said that sometimes no more than 

 seven have been definitely found. Hagen (5) gives seven 

 as the number of tubes in Osmylus.' Here I have always 

 found eight. In Chrysopa, where the common number is 

 also eight, I have tv/o cases in which there were quite defin- 

 itely only six tubes. Evidently there is occasionally some 

 variation. 



Colour and Markings, 



Colour is produced in several ways. The metallic lustre 

 of the eyes is a diffraction effect, since pigment here is 

 always dark crimson or black. Chitin pigmentation is 

 always brown, varying in intensity. It is fairly constant 

 in distribution for a given species. The head markings of 

 larvae are due to pigmentation of chitin. Hypodermal 

 pigment is common and fairly constant for a species. The 

 body markings of Chrysopid larvae and green colour of 

 adults, latero-dorsal bands of Hemerobiids, etc., are due 

 to this form of pigmentation. Colours produced by body 

 contents, alimentary canal, fat body, etc., are not so reliable 



