666 THE GENERATIVE ORGANS. 



2. DESCRIPTIVE ANATOMY OF THE INTERNAL GENERATIVE 

 ORGANS OF THE FEMALE BLOW-FLY. 



The internal generative organs in the female Blow-fly are a 

 pair of ovaries and a pair of parovaria ; the oviducts, the 

 utero-vaginal tube and its appendages the spermatophorous 

 sacs, which are three in number. 



The Ovaries. In the egg-laying female of the Blow-fly the 

 ovaries are a pair of discoid organs, which occupy the greater 

 part of the abdominal cavity and distend it so that its ventral 

 syndesmoses are extended to their full extent. 



Each ovary is oval in form, concave on its dorsal and 

 internal, and convex on its ventral and external surfaces ; 

 3'5 mm. in its long diameter, 3' mm. in its transverse diameter, 

 and i '5 mm. thick. 



These organs are so situated that they are only separated 

 from the ventral and lateral walls of the apex of the abdomen 

 by a layer of adipose tissue '75 mm. thick. They meet in the 

 middle line beneath the oviducts and intestine, and extend 10 

 the margins of the pericardial septum dorsally. They extend 

 forwards to the crop and the great air-sacs at the base of the 

 abdomen. 



Structure of the Ovary. Each ovary is enclosed in a thin 

 capsule of peritoneal tissue, which covers the whole gland and 

 is continuous with the peritoneal coat of the oviduct. 



Tin's capsule encloses the egg-tubes, of which there are from 

 right}' to one hundred, and sends incomplete septa between 

 tlii-m, thus dividing the cavity into as many loculi as there are 

 egg- tubes. 



The oviduct terminates in a pair of tubse, the tuba? of the 

 "vidtict, which are short and funnel-shaped. 



One of these tub;e is connected with each ovary ; it is united 



Di->ruiri n IN in I'l \ i K X LYII. 

 The internal generative organs of the female Blow-fly, f, fat bodies ; 0, ovary; od, 



oviduct ; /, parovarium ; /, tuba ; .f, sacculus : //, uterus ; and ; r , vagina. The 

 three ovoid bodies between the parovaria and the uterus are the spermathecu:. 



