PROF. OWEN ON THE ANATOMY OF THE INDIAN RHINOCEROS. 55 



appearance, with the fibres running forwards in a radiated direction'." There are no 

 fibres accompanying the radiated branches of the veins, showing the striated character 

 of voluntary muscle under the microscope. Mr. Thomas found that "the ciliary pro- 

 cesses were affixed to the crystalline lens ; " but on removing the anterior part of the 

 sclerotica, whilst the eye was suspended in spirit, both the vitreous humour and the 

 lens rolled out ; and the capsule of the lens showed no particular mark of the insertion 

 or fixation of the ciliary processes ; their impressions, in remains of pigmental matter, 

 were perceptible on the anterior part of the canal of Petit. The transverse diameter of 

 the lens was six lines, the antero-posterior diameter four lines. Mr. Thomas also states 

 that " the pigment was confined to the inside of the choroid^." But in both Rhinoceroses 

 dissected by me, I found on the outside of the chorion much loose cellular tissue, with 

 dark pigment : this coloured flocculent tissue concealed at first the ven?e vorticosse, 

 even when injected. The sclerotica is one line thick at the back part of the eyeball ; 

 and is thinnest near the middle of the ball, becoming thicker towards the cornea, which 

 is two lines thick. The choroid adheres pretty strongly to the back part of the sclerotic, 

 around the entry of the optic nerve, both by the entering vessels and by the tenacity of 

 its outer flocculent coat, especially where the vessels penetrate the sclerotica. There ; 

 is no tapetum luciduni. The lower eyelid has a special depressor muscle. __/ 



DESCRIPTION OF THE PLATES. 

 All the parts are of the natural size except when otherwise expressed. 



PLATE IX. 



Fig. 1. Metacarpal gland. 



Fig. 2. Metatarsal gland, laid open. 



Fig. 3. Excretory orifice of the gland. 



Fig. 4. External prepuce during the ordinary retracted state of penis (one-sixth 

 natural size). 



Fig. 5. Penis as protruded when this retromingent quadruped stales (one-sixth na- 

 tural size). 



Fig. 6. Glans penis, or the portion uncovered by the prepuce, when the organ is in 

 a state of erection (one-sixth natural size). 



Fig. 7. External parts of generation in the female (two-thirds natural size). 



Fig. 8. The two teats. 



PLATE X. 



Fig. I. Right tonsil, epiglottis, and back part of larynx. 



' Philosophical Transactions, 1801, p. 150. pi. 10. figs. 1, 2, 3. ■ lb. p. 150- 



VOL. IV. PART U, K 



