DEVELOPMENT OE THE OVAETES IN THE BLOWFLY. 



441 



in Monographien bearbeitet. Erste Monographic. Die weiblichen 

 Geschlechtsorgane der Kafer. Berlin, 1847. 



(25) Stuhlmann, F. — " Die Reifung des Arthropodeneies nach Beo- 



bachtungen an Insecten, Spinnen, Myriapoden und Peripatus." 

 Berichte der naturforsch. Gesellschaft zu Freiburg, Bd. i. 1886. 



(26) Weismann, a. — Die Entwicklung der Dipteren. Leipzig, 

 1864. 



DESOEIPTION OF PLATE XXVIII. 



Figs. 1, 2, and 3. Tkie uterus and its appendages in the adult egg-laying 

 insect. The different parts are indicated by the same letters in all the 

 figures. 



h. Bursa copulatrix. 



d. Duct of the gum-gland. 



gl. Gum-gland. 



m. Eetractor muscle of oviduct. 

 0. Ovary. 

 od. Oviduct. 



05. Terminal enlargement of the oviduct. 

 jp. Uterine pouch. 



s. Spermatophorous capsule. 

 ^l,t. Uterus. 

 V. Vagina. 



X. Attachment of the gum-gland to the ovary. 



Fig. 1. Dorsal view of the uterus. X 20. 



2. The same, with the ovaries. The parts rendered semitranspareut 



with glycerine, and seen by transmitted light. X 10. 



3. A median section of the uterus in the vertical antero-posterior 



plane. 



4. The ovary of a three-day-old pupa, c, capsule ; cl, cells of the 



cahx ; cs, egg-strings. X 200. 



6. Two of the egg-follicles from a ten-day-old pupa, cl, calicine duct ; 



OS, ovisac ; st, stalk of egg-follicle of the ovary ; Vs y, pseudo- 

 yelk-gi'anules of the pupa; x, cell-mass to which the stalks of 

 the ovisac are attached. X 300. 



6. An ovisac from a young fly. tc, terminal chamber; ec, egg- 



chamber ; st, stalk of ovarian follicle ; cl, calicine duct ; tr, 

 trachea. X 200. 



7. Another ovisac from a young fly, a little more advanced, y, edge of 



epithelium of egg ; ec\ ec", young egg-chambers. The other letters 

 as in figs. 5 and 6. X 300. 



