108 ON THE ANATOMY OP THE FLY. 



DESCRIPTION OF PLATE X. 



Fig. 1. The internal generative orgaes of the female seen from below 

 only a portion of the ovaries is represented, from a preparation stained 

 with carmine, x 15 diam. 



Fig. 2. The common oviduct and its appendages, viewed laterally, to 

 to show its muscles and bursa. x 30 diam. 



Fig. 3. The ovipositor seen laterally, during the deposition of an egg. 

 X 30 diam. 



Fig. 4. Plate between the rectum and ovipositor, x 30 diam. 

 Fig. 5. The last segment of the ovipositor, x 30 diam. 

 Fig. 6. The bursa copulatrix. x 40 diam. 



Fig 7. The seminal receptacles of the female from the right side 

 X 60 diam. 



Fig. 8. One of the ovarian tubes or follicles exhibiting four ova in 

 various stages of development a the germinal vesicle surrounded by 

 epithelium -like cells ; b the first stage of yolk segmentation ; c the 

 second stage of yolk segmentation, d the segmented yolk broken up and 

 surrounded by a zona pellucida. X 60 diam. 



Fig. 9. Yolk cells undergoing degeneration, a mature yolk cell, 

 b c & d the same undergoing degeneration, x 250 diam. 



Fig. 10. Upper part of an ovum, showing the first stage of the for- 

 mation of the germinal disc and yolk canal, x 60 diam. 



Fig. 11. The ovum just before impregnation, x 60 diam. 



Fig. 12. The upper extremity of the same, showing the micropyle, 

 germinal disc, and upper part of the yolk canal, x 150 diam. 



Fig. 13. The ovum, eight hours after impregnation, showing the larval 

 integment in the interior. X 60 diam. 



Fig. 13a. Cells from the larval integment of the same age. x 500 diam. 



Fig. 14. The ovum, twenty-four hours after impregnation, showing the 

 tracheal system of the larva just before its escape from the egg. x 60 

 diam. 



Fig. 15. A small portion of the ovicapsule at the time of impregnation. 

 X 200 diam. 



Fig. 16. Cells from the fat bodies of the adult larva, x 30 diam. 

 a, the same in the first stage of degeneration. 4, c, growth -corpuscle formed 

 from the same, and nucleated cells originating in the growth-corpuscles, 

 The former x 30, the latter X 300 diam. 



