PROFESSOR OWEN ON THE AYE-AYE. 75 



(ib. f) iis a simple undivided tube : it sends oif the internal iliac (n) at the usual place. 

 The posterior tibial artery is the only one which shows any disposition to break 

 up or quickly divide into a number of small branches ; these are distributed chiefly 

 to the muscles arising from the long tendons, or other parts, as flexors or adductors 

 of the toes. 



^10. Renal Organs. 



The right kidney (PL XXIV. fig. 1, k), situated as before described, is higher by half 

 its own length, than the left {ib. m)\ The right kidney is 12 lines, the left one is 

 11 lines in length, the latter being the broadest, viz. 9 lines, with proportionate 

 thickness. The cortical part (PL XXIV. fig. 10, e) is about 2 hues in thickness: the 

 tubuli of the ' medullary ' part (m) converge to a single short obtuse papilla (p). The 

 ureters (ib. fig. 1 1 , m) have the usual course and termination in the urinary bladder {ib. b). 

 The renal arteries ascend obliquely to reach the pelvis of the kidney. The adrenals 

 (supra-renal bodies, PL XXIV. fig. 1, u, u), proportionally larger than in the larger 

 Quadrumana, correspond in general shape with the kidneys ; but the right is narrower 

 in proportion to its length. 



The urinary bladder (PI XXIV. fig. II, 6) is of a longish oval form ; when moderately 

 distended, it measures about 1^ inch in length and an inch in diameter. The ureters 

 terminate in the usual oblique manner in the neck of the bladder. 



§11. Generative Organs. 



The testes are lodged in a sessile scrotal prominence on each side, and a little below 

 the base of the penis. Their vaginal tunic communicates by a contracted aperture 

 with the peritoneal cavity, into which they cannot be returned, but are permanently 

 external to it. 



The vasa deferentia (PL XXIV. fig. 11, ?^) take the usual course to the neck of the 

 bladder, and become slightly enlarged above their entry into the notch of a flattened 

 heart-shaped prostate. There are no vesiculse seminales. The prostate gland (ib. p) 

 is 5 lines in length by 4 in breadth, slightly concave on the broader posterior surface 

 which is applied to the rectum. The two anterior surfaces meet at an open angle, 

 along the middle of the fore part. The muscular part of the urethra, beyond the 

 prostate, is 7 lines in length : along each side of it is a flattened oval gland (ib. w) 

 6 lines by 4 lines, slightly concave behind and convex in front ; these answer to 

 ' Cowper's glands.' Their ducts penetrate the back part of the bulb. This part of the 

 urethra is 6 lines long by 3 in breadth, surrounded by an ' accelerator muscle ' of half a 

 line in thickness : the spongy structure of the bulb is exposed at /. The corpus caver- 

 nosum has a distinct septum, with a thick ligamentous capsule, as is shown in the 

 section of the penis (ib. fig. 1 2). The ' erectores ' (ib. fig. 11, e, e) have the usual origin 



' The mirror was not used in engraving the drawing, and the right and left sides are reversed in the Plate. 



L 2 



