220 THE VOYAGE OF H.M.S. CHALLENGER. 



base of tlie lung. The peritoneal fold or mesentery is shorter than the oviduct itself, 

 and consequently the latter is thrown into a number of sinuous curves, as represented in 

 PI. XVII. fig. 8. The duct commences close to the ovary by a dilated funnel-shaped 

 extremity, which opens freely into the cavity of the peritoneum. In Eudyptes clirysocome 

 the oviduct measures 6 inches in length. From its abdominal opening the tube, as 

 it passes backwards, narrows rapidly to a constriction, which is situated 1^ inches 

 behind its commencement. Behind this constriction, again, the tube to some extent 

 dilates, and continues of uniform diameter to within 2 inches of its cloacal orifice, 

 between which and the latter it is again somewhat expanded. The cloacal orifice is 

 situated on the upper wall of the posterior cloacal chamber, and occupies a corresponding 

 position to that of the left vas deferens in the male. Unlike the corresponding orifice 

 in the male, however, the left oviduct does not open on a papilliform eminence, but 

 directly into the cloaca, the orifice being undefended by any valve. The entire length 

 of the oviduct is lined by a soft mucous membrane, which is thrown into longitudinal 

 rugae, and presents no trace of the villous processes observed by Owen ' in this portion 

 of the oviduct of the common fowl. 



Variations. — The female organs in every species of Penguin exactly resemble those of 

 Eudyptes chrysocome above described, and difter only in size. Further remark is there- 

 fore unnecessary. 



Peculiar Glands. 



The Coccygeal Gland. 



The coccygeal gland (PI. X. fig. 5) is situated immediately beneath the skin of the 

 rump, and rests in part upon the levatores coccygis muscles, and in jiart upon the quills 

 of the large feathers of the tail. The gland consists of two lateral halves, each of which 

 presents the form of an elongated pear-shaped sack, the base of which is directed forwards, 

 the apex backwards. These two portions of the gland are closely united to one another 

 for the posterior two-thirds of their length, their posterior extremities terminating 

 on a large, conical, cutaneous papilla, which in Eudyptes chrysocome measures \ 

 of an inch in length. On the apex of this papilla are placed the orifices of the 

 two ^ ducts which convey the secretion of the gland to the surface of the skin. On 

 making a section of the gland, each half is seen to lie surrounded by a dense fibrous 

 capsule, in the interior of which is placed the true secreting structure. This again 

 consists of two parts, a dense circumferential, and a more centrally placed lax and 

 spongy tissue. The secretion is apparently prepared in the circumferential, whence 

 it passes into the central portion of the gland, which is composed of a quantity of 

 loosely arranged trabecular tissue, surrounding a central canal. AVith the latter the duct 



^ Cyclopedia of Anatomy, vol. i. p. 357. 



2 According to Owen, this papilla is "perforated by numerous orifices," Anatomj' of Vertebrates, vol. ii. p. 230. In 

 every species of Penguin there is but a pair of such orifices. 



