CETACEA—LILLIE. 101 
Mammary GLanps. 
The mammae of Megaptera were found to agree very closely with the descriptions 
of these organs in other members of the Balaenopteridae given by previous observers ;* 
so that it will only be necessary here to mention a few points which do not appear to 
have been hitherto recorded. There were two furrows, about 13 feet long and 3 inches 
deep, situated one on either side of the urinogenital opening, both of which contained 
a nipple. 
Near each nipple-groove, in the female, there was usually a smaller furrow without 
a nipple. This accessory groove either occurred on the outer side of each nipple- . 
groove or between the latter and the vulva. (See text-fig. 6, A.) 
In several dead females the nipples were protruded beyond the general level of 
js Saas os Ske 
Fic. 6.—A—Diagram to show the position of the nipple-grooves in the Humpback : 
a, anus ; b, vulva; ¢, nipple-groove ; d, secondary furrow ; ¢, alternative position 
of latter. B—Lateral view of walls of nipple-groove everted : a, nipple. 
the ventral surface of the whale, by the eversion of the walls of the nipple-grooves. 
(See text-fig. 6, B.) 
When everted, the walls of each furrow formed a dome-shaped swelling, with the 
nipple on its posterior side. The latter was thus raised about 3 inches above the 
general level of the surface of the body. When unprotruded it was nearly 3 inches 
beneath the surface. 
Iam unable to say whether this protruded condition of the teats was a natural 
occurrence, or was produced by abnormal causes after death. It was of interest, however, 
to note that it could occur, and could undoubtedly facilitate the process of lactation. 
That it was a natural condition of the teats is suggested by the latter function, and by 
the presence of erectile tissue around the nipple-region. Moreover, the looseness of the 
skin in this locality, together with the secondary furrows, would allow of the necessary 
expansion of the nipple-grooves for the protrusion of their walls. 
An elongated compressor muscle covered the posterior two-thirds of each 
mammary gland. 
The anterior bundles of this muscle arose in the superficial fascia between the two 
breasts, and passed across each gland in an oblique direction to their insertions in the 
* Hunter, J., Phil. Trans. Roy. Soc., 1787, p. 75, Pl. xxi. Turner, W., Trans. Roy. Soc. Edinb., 
Vol. XXVL., 1870, pp. 197-251. True, F. W., ‘‘ Whalebone Whales of the Western North Atlantic,” 
Smithsonian Contributions to Knowledge, 1904, Vol. XX XTIT., Pl. 20. 
VOL. I. Q 
