ANATOMY OF THE SONDAIC EHINOCEEOS. 195 



Owen for the Indian Rhinoceros ; as in that species, one of the three papillary muscles, 

 corresponding to the "great "or "anterior" papillary muscle of Man, is attached to the 

 free wall of the ventricle. This arrangement is found in many mammals either occa- 

 sionally or invariably, and is apparently characteristic of the Tapir and the Ungulata 

 generally. 



The aortic arch gives off an innominate artery, from which are derived the common 

 carotid and the right subclavian ; the left subclavian arises separately from the aortic 

 trunk ; each of the two subclavians gives off an internal thoracic artery, which is large, 

 as in Mh. indicus. The external and internal iliacs arise separately from the aorta. 



The origin of the arteries from the abdominal aorta is precisely like that of Man ; 

 the superior and inferior mesenteric arteries are quite separate, the one arising in front 

 of the other behind the origin of the renal arteries. In many of the lower Mammalia 

 there is but one mesenteric artery. 



For the account of the smaller branches of the arterial system reference must be 

 made to the description of the abdominal viscera. 



Urino-genital Organs. 



The kidneys showed slight indication of lobulation ; they were covered below by the 

 peritoneum, which did not extend on to the borders nor on to the dorsal surface. 



The urinary bladder had a very distinct urachus ; the muscular fibres of the bladder 

 were disposed in two layers ; the superficial fibres were arranged in a series of concentric 

 circles round the urachus. The deep fibres passed round the bladder in a direction as 

 nearly as possible at right angles with the superficial fibres. The superficial fibres 

 were extremely conspicuous and distinct from each other by reason of their large size ; 

 the deep fibres were much smaller and whiter in colour. Our observations upon the 

 generative organs do not entirely coincide with those of Sir Richard Owen upon the 

 generative organs of the Indian Rhinoceros ; it must be borne in mind, however, that 

 the differences which we here record may be actual differences between the two species. 

 The points in which we are at variance concern the structure of the vesiculse seminales. 

 These organs are described by Sir Richard Owen in the following words : — " The 

 vesicular glands or ' vesicula? seminales ' present an elongate subcompressed pyriform 

 shape, eight inches in length and three inches and a half across the broadest part of 

 the fundus. They have a lobulated exterior and a structure very similar to that of the 

 same bodies in man." On Plate xvi. of his memoir those structures are illustrated, 

 and the figure of the vesicula seminalis (v. s.) is entirely in accord with the description 

 given of them. 



We are nevertheless inclined to suspect that what Prof. Owen terms the vesicula 

 seminalis is in reality the vesicula seminalis plus a portion, at least, of the prostate 



The disposition of this part of the generative system in Rhinoceros sondaicus may be 



