46 PROF. OWEN ON THE ANATOMY OF THE INDIAN RHINOCEROS. 



Suprarenal glands. — These bodies, like the kidneys, differed from each other in form ; 

 they were elongated and nearly cylindrical. The right had one extremity bent at a right 

 angle : its length in the female Rhinoceros was three and a half inches ; its breadth across 

 the bent extremity two inches : the left was simply elongated, three and a half inches 

 long, one and a half broad and one inch thick. In section they presented an external 

 greyish-yellow fibrous cortex, from one-fourth to one-third of an inch thick, enclosing 

 a fleshy-coloured substance, in the middle of which there was a semilunar portion of the 

 grey fibrous matter : there was no trace of a central cavity. Both suprarenal bodies 

 adhered closely to the contiguous large veins. 



The urinary bladder presented nothing remarkable except a very distinct pit or cica- 

 trix, surrounded by a double concentric fold of membrane (PI. XIV. fig. 4, a), where 

 the duct of the allantois originally communicated with the cavity. 



Part III. 



Thoracic Viscera. 



The thoracic viscera presented much the same relative position as in the Horse ; the 

 lungs becoming narrow and elongated at the contracted anterior part of the thorax : the 

 distance between the pericardium and the diaphragm was relatively less than in the 

 Horse. 



The heart weighed 28 lbs. avoirdupois. The length of the undistended ventricular 

 part was one foot one inch ; the breadth of the ventricles was one foot three inches. 

 The pericardium was of great strength. The heart presented the short, obtuse form 

 which characterises it in the Elephant and Tapir. 



The superior precaval vena cava receives the right or common vena azygos close to 

 its termination at the upper part of the right auricle : two inches above this it receives 

 the right vertebral vein, which is about half an inch in diameter; two inches above 

 this it is formed by the junction of the left subclavian with the right subclavian vein. 

 At the concavity of the great vein formed by this junction, which concavity crosses the 

 fore part of the aortic arch, the bronchial veins and some small pericardial veins enter the 

 superior cava. The upper part of the superior cava receives the two large jugular veins 

 close together, so that a proper 'vena innominata' can scarcely be said to be formed. 

 The left vena azygos, which is formed by the union of a few superior intercostal veins 

 of the same side, terminates in the left subclavian vein, which receives separately the 

 left vertebral vein from the neck. The right or principal azygos receives the intercostal 

 veins of both sides as far forwards as its entry into the precaval vein ; the Rhinoceros in 

 this structure agreeing with the Horse. 



The coronary vein receives only a small pericardial vein, which descends along the 

 back of the left auricle, before it terminates with the inferior cava, at the base of the 

 right auricle. 



