THE FEMALE REPRODUCTIVE ORGANS 5 



The theca externa cells are fibroblastic, and continue un- 

 changed during the whole life of the follicle. After ovulation 

 the theca externa produces trabeculae which carry blood and 

 lymph capillaries into the developing corpus luteum. 



The accounts of the life history of the theca interna cells vary 

 greatly. In some species, such as the pig (Corner, I2i, 122), 



\^^'rV 



m.g. 



Fig. I. — Ovary of Mouse just before Puberty. 



Large follicles but no corpora lutea are present. 



c. connective tissue; d.p. discus proligerus; g.e. germinal epithelium; 

 /./. liquor folliculi; m.g. membrana granulosa; o. ovum; t. theca. 



and Ornithorhynchus (Hill and Gatenby, 299), they are de- 

 scribed as being small and flattened until just before ovulation 

 and then swelling up to a glandular type. Other authors, 

 however, describe them as undergoing degeneration on follicular 

 maturation or after ovulation {Dasyuriis : O'Donoghue, 477, 479, 

 480 ; Dasyurus and Didelphys : Hill and Gatenby, 299). 



The granulosa is made up of polygonal cells arranged irre- 

 gularly, except round the periphery and round the ovum, where 

 the arrangement is columnar. Most recent authors have 

 followed Pfliiger (517), de Winiwarter (639), and Waldeyer (628) 



