444 SC'Hl'LTK, SEI \VHALK. 



convex and distinctly tabulated, the dorsal nearly flat. Between them is a large thymic vein 

 which opens into the left brachiocephalic. The right measures transversely 7 mm., sagittally 

 6 mm., and has a thickness of 4 mm. ; for the left body these dimensions are respectively 8 mm., 

 6 mm., and 3 mm. 



Thyroid. The Thyroid has the form of a TJ; the isthmus is constricted and the lateral 

 lobes retort-shaped with their broad extremities rostrad. The gland is in contact with the 

 fundus of the tracheal sac, but has an asymmetrical position, the right lobe nearly sagittal, the 

 left with a distinct inclination laterad, to such a degree indeed that it is wholly concealed by 

 the left brachiocephalic vein, while the right appears in ventral view between the right vein and 

 the tracheal sac. The right lobe measures 13 mm. in length; its greatest breadth is 5 mm., 

 and greatest thickness 3 mm. The corresponding dimensions of the left are 7 mm., 5 mm., and 

 4 mm. It is thus not only asymmetrical, but the left lobe is also smaller. Near its rostral pole 

 on the left is a small oval body about 3 mm. by 2 mm., of glandular appearance, possibly one 

 of the parathyroids. The isthmus measures 4 mm. transversely, by 2 mm., sagittally. 



ABDOMEN. 

 (Plates LI-LI 1 1.) 



The abdominal cavity is broad, deep and capacious in its rostral portion; caudad it is a 

 narrow space of triangular cross-section bounded on its dorso-lateral sides by the great hypaxial 

 muscles and ventrally by the bladder, urachus and accompanying hypogastric arteries. The 

 conformation of the parts is such that the plane of the umbilicus affords a natural and convenient 

 division between these regions. The caudal margin of the umbilicus is approximately in the 

 same transverse plane as the tip of the last rib, in this specimen the thirteenth, and this rib 

 by its extremity is in relation with the first third of the kidney. The large rostral region of the 

 abdomen is thus at the sides wholly under cover of the ribs, its ventral closure being given by the 

 massive recti. The attachment of the diaphragm in the ventral midline is at the level of the 

 extremities of the sixth ribs, the highest point of the dome the caval aperture lies in the 

 fourth space vertically above the extremity of the fourth rib. The caval aperture is situated 

 in a transverse groove, which marks the abdominal surface of the diaphragm, dividing it into 

 a ventral slope corresponding to the pericardium and a dorsal slope, which on its thoracic aspect 

 corresponds to the diaphragmatic surfaces of the lungs and costophrenic sinus. The even slope 

 of this dorsal or caudal plane of the diaphragm is marked on each side by a shallow fossa; that 

 on the right is the result in the hardened specimen of moulding upon the right lobe of the liver; 

 that on the left upon the first compartment of the stomach. In addition to the viscera named, 

 the cephalic compartment of the abdomen contains the spleen and pancreas, the duodenum, 

 the colic loop and practically the whole of the jejuno-ileum, only a very few of its most caudal 

 coils lying caudad of the plane connecting the umbilicus with the last rib. Against its dorsal 

 wall, retroperitoneally, are placed the adrenals, the suprarenal segment of the postcava and the 

 upper poles of the kidneys. The liver predominates upon the right, approximately three fifths 

 of its bulk lying to the right of the midplane, caudally overlying the right kidney for nearly half 

 the length of the latter organ. To it caudally are closely applied the pancreas, the ampulla 

 duodeni, and the stomach, the gastro- hepatic omentum being reduced to little more than reflec- 



