38 THE NORTH AMERICAN SPECIES OF DROSOPHILA. 
the Drosophiline occurs also in Scatophaga (Cordylurine), and appar- 
ently in Parydra (Ephydrine). The two receptacles of Chiromyia 
minima Becker (Geomyzinz) are similar in structure to those of 
Aulacigaster leucopeza. 
TABLE 2. 




1 3 

2 

0 











Chloropine. Ephydrine. Agromyzinz. Borborine. Geomyzinz. 
Drosophiline. Borborinz. Drosophiline.! Helomyzine. 
Drosophiline. Ochthiphilinz. Ortaline.! 
Geomyzine. Ortaline. 
Loncheine. Phycodromine. 
Ortaline. Lauxaniine. 
Sciomyzine. Sepsine. 
Trypetine. 


1 Aulacigaster (3 receptacles) and Seoptera (4 receptacles) each have only two ducts. 
The ovaries consist of five or more egg-strings each. At the anterior 
end of each string lie the oogonial cells; at the posterior end is a 
mature egg. The region between is filled with eggs in intermediate 
stages of development. After oogonial multiplication has been com- 
pleted there are found to be cysts of oogonial cells surrounded by 
follicular envelopes. Each cyst contains 16 nuclei, of which one 
becomes the egg-nucleus and the other 15 belong to nurse-cells. 
These 16 nuclei are alike to all appearances until a relatively late stage.* 


* This account of the ovary is from Plough (1917). 
Since this paper was sent to press J. F. Nonidez (1920. Biol. Bull. 39: 207-230) has pub- 
lished a full account of the structure and physiology of the internal genital apparatus of both 
sexes of Drosophila melanogaster. 
