404 CETACEA. 



it had all the appearance of either terminating in the red glandular body or of being 

 connected in some way to the monilif orm tube proceeding from it. The course of 

 this vessel in the opposite direction lay towards another transparent, but smaller 

 sac (fig. 9 111"), lying somewhat nearer the chorion than the first mentioned and 

 larger sac. 



The intimate relationship subsisting between all of these structures, glands, 

 moniliform vessels, pedunculated glands and sacs, and their close connection with 

 the vessels devoted to the nourishment of the foetus, suggest the likelihood that they 

 are important elements of a glandular system subservient to the vascular system of 

 the chorion, and that the sacs are analogous to lymphatic hearts. 



Besides the arteries and urachus which have their usual relations, there is 

 another tubular cavity in the cord lying between the veins and the urachus, and 

 when the cord is cut across close to the abdominal wall two or more orifices may be 

 detected in the cut end leading into it. It has a length of about 5 inches, and is of 

 considerable capacity, being in some parts fully half an inch in diameter. In some 

 parts of its course it is divided into secondary channels by septa or folds extending 

 from one wall to the other, and also from part to part of the same wall. The inter- 

 spaces between the blood-vessels consist of a loose membrane, indeed so loose that a 

 probe passes easily along the orifices as they become distended when the cord is cut 

 across at intervals. YeUow glandvilar sacs are common on these areas, but are not 

 numerous near the funis, and in fig. 9 they are seen in the upper part of the draw- 

 ing chiefly in the mesial line and on one side. 



The veins and also the arteries of the cord communicate with one another, 

 and at about 10'25 inches in the case of the former and 10 inches in the latter, their 

 respective internal calibres are as 0"'20 to 0"'60. In the artery, the communication 

 is direct and is outwards from the smaller to the larger. But in the veins the channel 

 is iirst towards the foetus and then |backwards ; the orifice in the first vein forming 

 a kind of sac before the channel turns backwards to reach the other veins. In the 

 case of the arteries, the channel passes below the urachus from artery to artery. Below 

 this point, the larger artery presents a considerable dilatation of an elongated 

 character, and a number of large branches are given oflP from it and very many 

 small twigs. It is then continued on to the right side, branching in its course. 

 The smaller artery does not show any dilatation, and passes to the left side of the 

 chorion. Only very small twigs are given off from the arteries prior to their in- 

 osculation. The veins are dilated at intervals in their course prior to the inosculation 

 of the main trunks, but not to the same extent as in Flatanista. The vein from the 

 right side of the chorion, also like the artery, presents a great dilatation at the point 

 at which it lies alongside it, about an inch and a half below the anastomosis. But 

 no such enlargement occurs in the vein to the left side of the chorion which does not 

 receive so many branches as is the case with the vein of the right side. 



Minute structure of the^ ovary. — In transverse transparent slices of the ovary 

 of the foetus of Orcella brevirostris I found the cortical layer surrounding the 

 entire organ to be most numerously studded with ova (Plate XXXVII, fig. 10, o). 



