Female Organs 



115 



of insects. Both the capsules and ducts may be filled 

 with seminal filaments. 



The common oviduct, the spermathecae, and the gluten- 

 gland, all open close together into a deep intersegmental 

 fold at the junction of the eleventh and twelfth segments 

 of the larva (fig. 75, go, ggo). 



Before egg-laying the epithelium of the ovarian tubes, 

 and apparently that of the small egg-chambers, are 

 completely absorbed. 

 In a female fly, taken 

 just before egg-lay- 

 ing, thin sections re- 

 vealed hardly any- 

 thing within the 

 abdomen excej)t the 

 eggs, the gluten - 

 gland, the sperma- 

 thecae, the shrivelled 

 alimentary canal, and 

 the unaltered Malpi- 

 ghian tubules. A 

 clear, thin line sur- 

 rounded each egg, 

 which we took to be 

 the last trace of the 

 wall of the ovarian 

 tube. In some places 

 this was found lying in actual contact with the epidermis 

 of the body- wall. 



The external female organs are described on p. 104. 



During copulation the spermathecae are filled with 

 seminal filaments from the male. One egg descends 

 from each ovarian tube, the others remaining un- 

 developed. It is not known where fertilization is effected. 

 The very numerous eggs as they pass out are enveloped 



I 2 



Fic 86. — Female organs removed from the 

 larva, s, spermatheca. (/, gluten-glaud. 



