Structure and Infe-history of the Holly-fly. 277 
backwards, so that it forms an inner conical chamber 
BIGGS lp. 
Transverse section through 7th segment ; the plane of this section is posterior 
to that of fig. 14. d, ventral diverticulum of uterus ; ex, conical extension of 
7th segment, containing 8th and 9th segments (retracted), giving attachment 
laterally to the oblique muscles, and ventrally to the muscular tissue sur- 
rounding the uterus; ggl, ducts of gluten-glands; rs, fused ducts of sperm- 
receptacles; s, 9th segment enclosed in 8th; wu, uterus; wu’, thin-walled 
region of uterus. (x 140.) 5 
enclosed by the 6th segment (fig. 13). From the wall 
of this chamber and from its inner surface spring the 
RiGee Os 
Ovipositor of fly, lateral view. The 9th segment is partly retracted into the 
dentigerous 8th segment ; the posterior end of the 7thsegmentisshown. (xX 120.) 
retractor-muscles of the ovipositor, while to the outer 
lateral surface is attached a set of oblique muscles (figs. 
