482 CETACEA. 



the pavilion on the right side is much more contracted than on the left (PL XXXII, 

 fig. 3), which is wide and patulous. They hoth look forwards. Springing from 

 the superior external margin of the ovary is a prominent fimbria ovarica, which 

 is prolonged outwards along the superior margin of the pavilion, on the inner aspect 

 of which there is a deep pouch at its base. This pouch is formed by a broad 

 transverse fold that passes between the ovarian attachments of the margin of 

 the pavilion. In Orcella this fold is further removed from the ovary and consti- 

 tutes a broad veil on the inside of the pavilion, dividing it into two chambers. 

 In Flatanista the margins of the pavilion are attached at the outer extremity 

 to the margins of the ovary, but in Orcella in the impregnated female one 

 border is continued as a delicate membrane along the Eallopian tube as far as 

 the horns. 



Minute structure of Fallopian tube. — This tube in P. gangetica consists of 

 the most remarkably extensile tissue. A very small fragment, about one-half 

 of an inch in length, when freed of its external peritoneal coat is capable of 

 being extended to nearly one yard in length. The fibrous structure which 

 manifests this remarkable property resembles the fibrous layer of the uterus. In 

 both the virgin and maternal oviducts, the walls are thrown into well-marked 

 longitudinal folds, which, however, are best seen in the former. The wall of 

 the tube is lined with a well-defined coat of columnar epithelium overlying a 

 richly corpusculated fibrous layer, resting on another layer of much longer wavy 

 fibres, with fewer corpuscles, and to which the expansibility of the tube is chiefly 

 due. 



Utricular glands in the foetal and in the virgin uterus, — I have pointed out 

 (ante, p. 397, PL XXXYIII, figs, 5, 6 and 7) that these structures are absent in the 

 foetal uterus of Orcella. 



In Flatanista, however, utricular glands are well developed in the foetal womb 

 (PL XXXVIII, figs. 1 and 2), indeed almost to the same extent as in the unimpreg- 

 nated uterus of the adult animal (fig. 4). This observation shows that it is unsafe 

 to form an a priori judgment as to whether these glands should, or should not, exist 

 in foetal uteri, because Professor Turner, who is generally distinguished by great 

 scientific caution, states that utricular " glands are not formed during intra-uterine 

 life, and it is probable that they are not fully developed until the uterus reaches 

 the stage of sexual maturity." 



Under the microscope, each gland appears as a distinct system in the virgin (fig. 

 4), depending in a highly- branched manner by a single tube from an orifice in the 

 cylindrical epithelial surface-layer, situated in a slight depression of the mucosa. 

 Together, the glands constitute a considerable mass, forming one-fourth or so of the 

 total thickness of the walls, and are closely packed against each other, but very 

 minute compared with the glands of the gravid uterus (fig. 8), than which also 

 they have a much more decidedly vertical arrangement, the glands in the 

 gravid uterus becoming stretched out by the extension of its waUs. They would 

 appear to be as numerous in the foetal and virgin as in the gravid uterus, 



