SCHULTE, SEI WHALE. 447 



remainder of the second stomach by an obliquely longitudinal ridge, which beginning near the 

 middle of the greater curvature extends distad across the dorsal wall and reaching the lesser 

 curvature changes direction, becomes transverse, and passes to the ventral wall. Here about 

 midway between the curvatures it declines abruptly running out into small ridges which diverge 

 towards the greater curvature. Beneath the arch of its transverse segment is left a small orifice 

 of dorso-caudal position that is in the region of the dorsal paries and greater curvature - 

 which leads into the third compartment. A furrow on the ectal surface is associated with the 

 proximal obliquely longitudinal segment of this ridge. It is very shallow and not of such a 

 character as to suggest that the ridge may be the result of post mortem compression or shrink- 

 age. A fold of that kind is present on the ventral wall of this compartment; it is easily obliter- 

 ated by manipulation and has no resemblance to the formation we are considering, which is 

 of solid massive structure. The portion of the second stomach distal to this ridge is marked 

 by transverse folds of the mucosa and although it produces little external protrusion, evidently 

 corresponds to Jungldaus's description of "einer relativ tiefen, ventralen, rinnenartigen Aus- 

 buchtung auf der linken Seite; dieselbe fuhrt direkt auf das Orificium des dritten Magens. " J 



The third compartment, defined against the second on the ectal surface by the slight 

 furrow already mentioned, is distally without surface demarcation from the fourth stomach. 

 Entally its boundary here is given by a ridge on the rostro-ventral wall, which displaces the 

 orifice of communication to the region of the greater curvature dorsally. Thus both entrance 

 and exit are adjacent to the greater curvature and of dorsal position. A third fold of inter- 

 mediate size and corresponding to an ectal sulcus and angulation of the tube is placed between 

 the other two. This springs from the dorsal wall and greater curvature leaving but a small 

 communication close to the lesser curvature vehtrally, to maintain the lumen of the compart- 

 ment, which thus is rendered canal-like and of the shape of inverted U, for the intermediate fold 

 is broad as well as high and appropriates a large part of the space between the other two folds. 

 The mucous surface is smooth and shows no trace of other folds. The diameter nowhere exceeds 

 2.5 mm., the orifices are distinctly less. Its length is 6 mm., its diameter externally is 5.5 mm. 



In older foetuses of B. musculus Jungklaus describes a third compartment of radically 

 different conformation. It was dilated, of thinner walls than the others, and defined by two 

 changes of direction in the axis of the stomach, with resulting angulation and the formation of 

 double separating walls at both its distal and proximal extremities. The two angulations of 

 the distal portion of the stomach in this foetus are incident, one at the middle fold of the third 

 compartment, one in the terminal portion of the fourth stomach. It is difficult therefore to 

 see in this stomach a stage antecedent to those of Jungklaus, for the supposition that such 

 angulation can be effaced and new ones form has no observations to support it. This raises 

 the question of divergence between the species of the genus in this character, a possibility which 

 is in a measure suggested by the wide discrepancies in the literature of the third compartment 

 in the adult. 



The fourth compartment presents a change of direction in its course. In its proximal and 

 longer portion its axis runs caudad, dorsad and to the right, in its short distal segment, rostrad, 

 dorsad and very slightly to the left. This change is effected by a gradual curve on the greater 

 curvature, but on the lesser is accompanied by a sharp angulation, immediately beyond which, 



1 Jungklaus, F., op. cit., p. 49. 



