ON THE LIFE HISTORY OF UGIMYA. H 



end of the egg-tube proper, there is formed a chorion ( /*; ). It is of 

 a somewhat chitinous nature, and bears hexagonal markings. Later it 

 hardens and forms an egg-shel]. At this stage, the egg assumes an 

 almost elliptical fonn tapering slightly at one end, and rounded at the 

 other, the longest and shortest diameters being respectively 0.25 mm. 

 and 0.15 mm. A micropyle ( P/. 77, y/f/. 5 ^ ) is found at its taper- 

 ing end. 



It is very difficult to make out the mode of formation of the chorion. 

 I believe that it is formed by a process somewhat like delamination 

 from the epithelial cells round the eggs. 



When the eggs in the egg tube proper are perfectly ripe, they are 

 carried down into the oviduct, and are then introduced into the anterior 

 portion of the vagina ( Fl II, fig. 3 c) where they are fertilized by the 

 spermatozoa from the seminal receptacles, ( d ) and are enveloped by a 

 transparent gelatinous sticky substance which is secreted by the tubular 

 glands (e). In this stage; the chorion assumes a light yellow color. 

 The largest eggs found in the ovarian tubes are 0.25 mm, and 0.15 

 mm. in length and breadth respectively ; but when they descend 

 into the vagina, they grow larger, their length and breadtli becoming 

 respectively 0.3 mm. and 0.2 mm. Generally the eggs seem to com- 

 plete their development in the anterior portion of the vagina, for I 

 have always found that the eggs in the posterior portion already con- 

 tain tiny maggots. The eggs which are found in the posterior portion 

 of the vagina have the shell which becomes somewhat brittle tinged 

 brownish black. When examined under a microscope, the convex side 

 of the shell is colored deep brownish -black and is thick in texture, 

 while the opposite flattened side is much lighter in color and thinner. 

 If we ins[)ect the flattened side with transmitted light there may be 

 seen through the egg shell, a tiny maggot developed in its interior 

 ( PL II, fig. 7 ). The contained maggot always lies with its dorsal 



