ANATOMY OF MEGAPTERA LONGIMANA. 9 



the cavity for the penis; it then narrows backwards to the 

 mammillary pouch, and is narrow from that to the anus. 



Mammillary Pouch. This interesting part in this male 

 Megaptera is situated 1J feet behind the preputial opening 

 and 2 feet in front of the anus. 1 The following is the 

 arrangement (see fig. 4, natural size): The opening of the 

 marsupium, elliptical in form, is from 1J to 2 inches in 

 length, more sharply marked behind, grooved for \ inch at 

 the fore-end ; breadth f inch ; the margins soft from the loose- 

 ness of the subcutaneous tissue. The black colour continues 



1 Referring to Pallas having first noticed the presence of mammillae in the male 

 cetacean, in the Beluga, Eschricht mentions particularly that their presence in 

 male whales, foetal and adult, has been well known to him. There is no reason 

 why the milk glands should not be present in male whales as well as in male 

 land mammals ; they cannot be more functionless in the former than they are in 

 the latter, or than they are in man. The point of interest is how these 

 significant rudiments are variously disposed. Eschricht found them present 

 in all male cetacean foetuses "an der Mittellinie des Bauches ein Paar 

 kleine schlitzenformige Offnungen," and that in the male porpoise (phoccena) " sie 

 nach aussen hie^ zu\ einer einfachen Offnung verschmolzen sind" (loc. tit., 1849, 

 p. 83). Professor Flower (Proc. Zool. Soc., 1865, p. 701) found the arrangement 

 in an adult male B. musculus to be that of two fissures, about 10 inches long, 1^ 

 inch deep, and 3 inches apart, slightly converging posteriorly, each containing 

 a nipple. The two-fissure arrangement, one on each side, more resembles that 

 of the female. John Hunter described the position and structure of the 

 mammary glands and nipples in the female cetacean (Phil. Trans., 1787), 

 and figured the nipples in their fissure in a 17-feet-long B. rostrata (Table xxi. ). 

 He describes the nipple as lodged in a sulcus on each side of the opening of the 

 vagina, surrounded , by loose texture, and, external to this, another small 

 fissure, "which I imagine is likewise intended to give greater facility to the 

 movements of all these parts." As these parts in my 14^-feet-long B. rostrata 

 (1870) are preserved, I may here mention that they differ from Hunter's figure 

 in the accessory fissure, instead of rather shorter, being much longer than the 

 mammillary fissure. Length of accessory fissure 5| inches on the left side, on 

 right side 4 ; length of the mammillary fissure, 2 inches on both sides. The 

 right accessory fissure passes as far back as the mammillary fissure, the left 

 f inch farther back. Breadth of skin between the two fissures 1 inch, being 

 about the same as that between the vulva and the mammillary fissure. The 

 nipple lies behind the middle of the fissure, concealed in it, \ inch or more from 

 the surface, is flattened and now about \ inch in height, and is surrounded by a 

 deeper and softer part of the fissure. An aperture in the summit admits a crow- 

 quill, and a little way along the duct, in the nipple, two or more apertures are 

 seen. The accessory fissure is deeper than the mammillary fissure. In my 16- 

 feet-long B. rostrata (1877) the accessory fissure has not been preserved. The 

 mammillary fissures are each 2 inches in length. The middle J of the fissure 

 forms a special fossa round the base of the nipple, 1 inch deep from the surface, 

 thrice as deep as the anterior and posterior parts of the fissure. The flattened 

 nipple is \ inch in height. 



