MANUAL OF ZOOLOGY 



SECT. 



The left ovary (ov) is a large organ in the adult bird, its 

 surface studded with follicles or ovisacs, varying in size 

 from about 15 mm. in diameter downwards, and each 

 containing a single ovum. The left oviduct (I. od) is 

 long and convoluted ; its anterior end is enlarged to form 

 a wide, membranous coelomic funnel (/. od") into which the 



or 



1,0(1, 



FIG. 292. Columba livia Male 

 urino-genital organs, adr, ad- 

 renal; cl. 2, urodaeum; cl. 3, 

 proctodaeum; k, kidney; ts, 

 testis, that of the right side dis- 

 placed; ur, ureter; ur', aper- 

 ture of ureter; vd, vas deferens; 

 vd' , its cloacal aperture; v. s, 

 vesicula setninalis. (From Par- 

 ker's Zootomy.') 



FIG. 293. Columba livia. Female urino- 

 genital organs, cl. 2, urodaeum ; cl. 3, 

 proctodaeum; k, kidney; /. od, left ovi- 

 /. od", 

 lomic 



aperture; ov, ovary; r. od, right oviduct; 

 r. od' , its cloacal aperture; ur, ureter; 

 ur' '. its cloacal aperture. '(From Parker's 

 Zootomy. ) 



duct; 1. od' , its cloacal aperture; /. i 

 its coelomic funnel; /. od'", its coelf 



ripe ova pass on their liberation from the ovisacs ; the rest 

 of the tube has thick, muscular walls, lined with glandular 

 epithelium, and opens into the urodaeum. 



Internal impregnation takes place. As the ova or 



