THE REPRODUCTIVE ORGANS 



381 



THE VAGINAL BAND 



The vaginal band is a unique structure which is of sufficient interest to be considered 

 separately from the other external genitalia. It was first noticed in a specimen of the 

 external genitalia of a Fin whale sent to England from the South Shetlands by Mr J. E. 

 Hamilton. It was then thought to be an abnormality of an interesting type, but the 

 examination of whales at South Georgia and Saldanha Bay shows that it is by no means 

 a rare occurrence among Fin whales and so should be included in any description of 

 their structure. 



In most immature female Fin whales, as already mentioned, the genital groove is 

 closed so that little or nothing can be seen of the genitalia ; and when the blubber is 

 removed the vulva is frequently removed with it. This probably accounts for the fact 

 that no mention of a vaginal band appears previously to have been made. 



The clitoris is an incurved, keeled structure about 8-o cm. long, with a trilobed apex 

 directed backwards. Under the clitoris are the openings of a pair of small glands; and 

 immediately behind these, between a pair of fleshy lobes, opens a larger unpaired duct 

 which is the urethra. Behind the urethra and nearly covered by the apex of the clitoris 

 is a small projecting mass of tissue with papilliform appendages. From the posterior 

 side of this mass stretches a thick strand 7 or 8 cm. long and not less than i cm. in 

 diameter, across the large, somewhat star-shaped entrance to the vagina, to the posterior 

 border of which it is attached (Plate XXXIX, figs, i, 2 and 3). 



In mature Fin whales one end of this band was sometimes found as a tag 5 or 6 cm. 

 long usually attached anteriorly, but signs of recent rupture of a complete band were 

 not found. 



The band is composed mainly of fibrous connective tissue with a few small blood- 

 vessels. Many minute convoluted ducts 

 course through the tissue, which also con- 

 tains a few droplets of oil. Transverse sec- 

 tions show that the character of the band is 

 not similar throughout. That part — about 

 one-third — which faces the opening of the 

 vagina is covered with papillae. At each 

 side the papillae give place to a typical epi- 

 dermis which covers the remaining two- 

 thirds of surface and resembles the epi- 

 dermis covering the blubber (Fig. 117). 

 Sections give the impression that the outer 

 surface epidermis has grown in round a 

 solid strand of the underlying tissue but 

 has not completely covered the inner surface. 



Of the total of 145 immature female Fin 

 whales, the band was present in 31 (21-4 per cent) and in the total of 206 mature Fin 



Fig. 117. Section of the vaginal band. 

 V, ventral, or outer surface. 



