478 CETACEA. 



extremity of a wide chamber, 1*10 incli in length, the walls of which consist of a 

 strong fibrous structure thrown into tendinous bands and marked by a few crypts, 

 the openings of lacteal canals. The outer surface of the external half of this 

 chamber is invested by a sphincter muscle for expelling its contents and keeping the 

 orifice leading to the canal closed. The chamber at its anterior end contracts to a 

 moderately small orifice surrounded by a loose fold of the tendinous wall, that hangs 

 so freely into the chamber as almost to resemble a valve. Placed immediately before 

 it, is the capacious cavity into which all the larger ducts pour their secretion. This is 

 1*25 inch in length, by 0-50 in breadth, and its wall has the same tendinous character 

 as the former. Anteriorly it is continued on into the gland as a duct, 0-20 inch in 

 width. Numerous ducts open into this chamber from all directions, each orifice 

 being marked by an arched fold ; on compressing the mammary slit of a living 

 gravid female a clear pale amber-coloured fluid, with a distinctly saltish taste, was 

 squirted out with considerable force. It dried on the fingers like a varnish and 

 was very sticky in drying. It consisted almost entirely of albumen. 



The gland itself is fully 6 inches long with an average breadth of 1'50 inch, 

 and it extends 3 inches anterior to the commencement of the duct at the head of 

 the second chamber, and is placed parallel to the outline of the vulva, 1 inch below 

 the surface. It is a pale yellowish structure of considerable consistence. 



The extensile nature of the tissues surrounding the two chambers must admit 

 of their being considerably distended with milk when the gland is active, and the 

 probability is that the milk is squirted into the mouth of the young. The long snout 

 of the young with its formidable array of teeth, and the circumstance that the skin 

 is tightly drawn over it, and that the applied surfaces of the upper and lower jaws lie 

 between the rows of teeth render it highly improbable that the young is fed through 

 the extremity of the snout. The concave surface, however, at the base of the snout 

 seems admirably adapted for application to the mammary region of the mother, and 

 it seems likely that the young rises sideways to the nipple, so that the side of 

 the mouth with its fleshy lips is brought over the mammary region, and that the milk 

 by the pressure is squirted into it. In the living gravid female which came under my 

 observation the slightest pressure exercised around the mammary slit caused the lacteal 

 fluid as I have said, even before the birth of the foetus, to be squirted out to a 

 considerable distance. 



Vulva in young and adult stages. — In the virgin, measuring 57 inches, the 

 vulva is 2*18 inches long, and in the gravid female 4'36 inches. In the former the mam- 

 mary slits lie nearly in a line with the labia majora, but in the adult they become more 

 external. The clitoris (PI. XXXII, fi^. 2, cl) is well developed, and in the virgin 

 where its true form is best seen, it consists of a bilobular glans, beyond which pro- 

 jects a filiform process resembling the tubular termination of the male urethra, and 

 in the virgin at the anterior margin of the base of the glans there is a mesial rounded 

 eminence, which, however, in the adult has become shrivelled into folds. In the 

 virgin the glans is half an inch in length by 0*36 inch in breadth, and the filiform 

 process has the same length. The division between the lobes of the glans is very 



