344 DISCOVERY REPORTS 



Laws (1957) examined the distribution of corpora albicantia and corpora lutea in 394 fin-whale 

 ovaries and found the probability that the corpora are not randomly distributed to be highly signifi- 

 cant. For 30 ovaries for which the orientation was known 74-1 % of the total corpora were in the 

 anterior half. In 32-7% of ovaries with two or more corpora they are entirely confined to the anterior 

 half of the ovary. The position of the corpora in relation to the long axis of the ovary was measured 

 in 96 fin-whale ovaries. This shows a progressive decline in the frequency of corpora at increasing 

 distances from the anterior pole, and they are completely absent from the posterior third of the largest 



ovaries. 



Relations 



Ommanney (1932) has described the position of the ovaries in relation to the reproductive tract in the 

 foetus. An adult female and an immature female have been examined closely in connexion with the 

 present study and will be briefly described. 



In the foetus the ovary lies free on the broad ligament and the triangular fibrous sheet extending 

 from the ovarian funnel does not cover the ovary (Ommanney, 1932, figs. 12 and 13). 



One ovary of a 75-ft. pregnant female weighed i-6kg. and measured 27 x 12 x4 cm. It bore a 

 corpus luteum, weight 0-7 kg., diameter 10-3 cm., and three large corpora albicantia. The other ovary 

 weighed 0-65 kg. and measured 25 x 12x3 cm., but had no corpora. The transparent fibrous sheet 

 extending from the ovarian funnel was rhomboid in shape and measured 60 x 50 cm., the longest axis 

 stretching from the anterior pole of the ovary to the uterine horn. The ostium abdominale was situated 

 just anterior to the intersection of the two main axes. The edges of this sheet were free except where 

 it was attached by a short ligament in the vicinity of the anterior pole of the ovary, and by a longer 

 and more slender ligament medially to the uterine horn ; in contrast to the foetus it was not attached to 

 the posterior pole of the adult ovary. This sheet is normally folded lengthwise so that it invests the 

 anterior part of the ovary and is attached to the broad ligament along the line of this fold. It cor- 

 responds to the funnel-shaped pouch described by Harrison (1949) in Globicephala melaena, and as in 

 that species the inner aspect is lined by numerous membranous ridges running inwards to the ostium, 

 which is lined by ciliated fimbria. The short ligament attaching the anterior end of this pouch was not 

 observed to continue to the ostium abdominale in this specimen as described by Daudt (1898) and 

 Ommanney (1932). An immature female 61 ft. in length had ovaries 24x5-2x2 cm. in size; the 

 relations of the ovary were similar, but the pouch differs somewhat from that of the pregnant female. 

 It over-arched the anterior two-thirds of the ovary and resembled the bursa ovarii of the dolphin 

 Stenella figured by Burne (Fraser, 1952, fig. 33) or the 'delicate arched covering or pavilion' of 

 Globicephala (Murie, 1873). In this immature female a conspicuous fimbriated groove extended from 

 the anterior pole of the ovary to the foremost edge of the ostium abdominale. This was described by 

 Ommanney (1932), but was not observed in the pregnant female described above. 



The Fallopian tube lies on the broad ligament partly covered by the ovarian sac. In the pregnant 

 female it was 61 cm. in length when straightened out. At the ostium abdominale the diameter of the 

 lumen was 4-0 cm.; at a distance of 20 cm. from the ostium it was 1-5 cm. in collapsed diameter and 

 lined by numerous longitudinal folds, and a further 20 cm. from the ostium it had narrowed to 4 mm. 

 and had four longitudinal folds. For the first two-thirds of its length it was sinuous, and then almost 

 straight; where it entered the uterine horn there was no papilla or constriction. The Fallopian tube 

 of the immature female measured 49 cm., the first 22 cm. next to the ostium being much folded and 

 the remainder more direct. The lumen was 1-75 cm. in diameter at the ostium, 1-25 cm. at a distance 

 of 10 cm. from the ostium, 1-05 cm. at 20 cm. distance and 0-3 cm. at 30 cm. distance. For the first 

 half the epithelium was much folded, but regular longitudinal folds appeared in the second part. 



From the anterior pole of the ovary a large fold, the plica diaphragmatica, runs lateral to the 



