SCHULTE, SEI WHALE. 465 



where the first forms a transverse ridge with a notched margin, like the fully developed folds 

 farther rostrad. The latter are largest at the middle of the dilatation and all of them present 

 the characteristic crenate appearance. Several points of difference emerge in the comparison 

 of this with Daudt's older foetus of B. musculus. In his specimen the annular folds were more 

 numerous, and the distal smooth portion of the vagina was relatively short. This makes it 

 highly probable that the region of the folds is during development extended caudad. Of this 

 extension by formation of new folds there is further evidence in the rows of tubercles referred 

 to above. Nor is the process apparently ended in Daudt's foetus of 121 cm. For here in addi- 

 tion to twelve well formed rings, were a few of little prominence and not completely encircling 

 the vagina. These are described as follows; "Die ersten unteren Ringe sind nur durch hoheres 

 Hevorspringen der einzelnen Faltchcn veranlasst, wahrend bei den folgenden auch immer der 

 betreffende Teil der Vaginalwandung mit in das Lumen einspringt und so ein Glirtel bildet, 

 worliber die Falten verlaufen." It would appear therefore that the formation of the annuli 

 is accomplished by the appearance of tubercles, which at first involve only the mucosa, with the 

 secondary formation of annular folds, upon which the primary elevations appear as crenations. 

 In the second place the folds in Daudt's foetus fall into two sets, a proximal with their edges turned 

 towards the uterus, a distal turning their margins toward the vulva. Between the two sets 

 is an especially well developed fold, with a T-shaped cross section. The equivalent of this fold 

 is not present in this foetus. The fourth and fifth folds are slightly undermined on the caudal 

 aspects, but the others are not inclined in either direction. For the most part also the rings 

 are incomplete, the ridges of the ventral and of the dorsal walls being independent and inter- 

 locking at the sides. 



ANGEIOLOGY. 

 (Plate LIII, Fig. 2). 



Arteries. Only the aorta and the proximal portions of the great vessels were examined 

 and these correspond so closely to Turner's 1 description of their arrangement in B. Sibaldii 

 ( = musculus) as to require but the briefest mention here. The aorta arching over the root 

 of the left lung reaches the vertebral column on the left of the fifth thoracic vertebra, and arriving 

 at the median line at the level of the diaphragm there continues to the haemal canal within the 

 arches of the chevron bones. The branches of the arch are a brachiocephalic, left common caro- 

 tid and left subclavian. The distance between the first and second is very considerable, de- 

 pendent no doubt upon the width of the trachea. The left subclavian arises from the dorsal 

 aspect of the arch. It then ascends to the rostral margin of the first rib and passes on its way to 

 the flipper, ventral to the scalene. In its arch over the first rib, and this is true of the right as well, 

 it is widely separated from the dome of the pleura, which does not extend beyond the caudal 

 margin of this rib. On each side an artery arches over the dome of the pleura, and produces 

 a slight groove on the apex of the lung; this is the posterior thoracic of Turner, a branch of the 

 subclavian, which is traceable into the thoracic rete. The descending aorta gives off the twelve 

 pairs of intercostals, the more rostral of which ascend sharply to reach their respective spaces. 



1 Turner, W. An account of the great firmer whale (Balomoptera Sibaldii), stranded at Longnicldy. Ft. 1. The soft parts. Trans. 

 Ruy. Soc. Edin., Vol. IV, 1872. 



