102 “TERRA NOVA” EXPEDITION. 
superficial fascia on the outer side of each breast. The posterior bundles arose at a 
point immediately below and in front of the nipple, and were inserted laterally, as in 
the case of the anterior bundles (text-figs. 7, e, 8, A). Each mammary gland consisted 
of a flattened oblong body, which passed from the nipple in an anterior and slightly 
dorsal direction. (See text-fig. 8, A). 
In a female 40 feet in length, which was suckling a calf when killed, the gland 
was 53 feet long, by 14 feet broad at its widest part, just im front of the nipple. The 
Fic. 7.—Ventral view of a Humpback, with the coat of blubber removed, to show 
superficial muscles (diagrammatic) : a, mylohyoid muscle ; b, pectoralis major ; 
c, umbilicus ; d, vulva ; e, compressor muscle of left breast. 
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Fie. 8..-A—Ventral view of left mammary gland of a Humpback: the thick line 
marks outline of gland ; compressor muscle indicated with fine lines: a, nipple. 
B—Longitudinal section through gland: a, nipple with narrow duct; b, wide 
portion of central canal. 
nipple contained the narrow mouth of a relatively wide canal, which traversed the 
centre of the gland throughout its whole length. In the broad portion of the breast 
above-mentioned, the canal was dilated into a spacious reservoir. A large number of 
ducts united with the central canal and ramified in the substance of the gland. (See 
text-figs. 8, B, and 9.) It would appear that the central canal is an elongated 
false teat. 
The milk collects im the reservoir, and by the contraction of the compressor 
muscle a stream of the fluid is forced through the nipple into the mouth of the calf. 
The latter is quite unable to draw off the milk from the breast by sucking, after the 
