104 THE VOYAGE OF H.M.S. CHALLENGER. 



fourth metatarsal, and they hint that this may possibly represent the abductor ossis 

 metatarsi minimi digiti transferred in this instance to the annular digit. In the 

 Hyrax which I examined I observed the thick ligamentous fascia upon the os calcis, but I 

 could detect no muscular fibres in connection with it. I should imagine that this fascia, 

 and the muscular fibres when they exist, undoubtedly represent that muscle undergoing 

 retrograde changes. 



Nervous arrangements. — The foot of the Hyrax presents one of the few instances in 

 which we find a deviation from the usual and typical plan of nerve supply. The internal 

 plantar nerve gives off a deep branch which sinks into the sole between those tendons of 

 the flexor longus digitorum which go to the index and medius ; after supplying twigs to all 

 the intrinsic muscles of the index, this branch pierces the adductor indicis and euds in 

 branches to the second dorsal interosseous muscle. The external plantar sends off a very 

 minute deep division, which gives twigs to the flexor brevis annularis, and then dips 

 under cover of the adductor annularis which it supplies. 



Although I made a dissection of both feet of the specimen, I was unable to make 

 out with precision the nerve-supply of the flexor brevis medii. 



In dissecting the manus I was much interested to find that the same peculiarity 

 in the nerve arrangements existed there. The median nerve supplies the muscles of 

 the index, and ends in the outer head of the flexor brevis medii. The ulnar nerve 

 supplies the muscles of the minimus and annularis. 



The second dorsal interosseous muscle, which is supplied by the internal plantar in the 

 foot, is absent in the hand. The fact of the outer head of the flexor brevis medii of the 

 hand being supplied by the median may simply indicate that it contains in its midst the 

 fibres of this lost interosseous muscle. In the manus, therefore, no less than in the foot, 

 I am still doubtful as to the nerve supply of the short flexor of the middle digit. 



Pkoboscidea. 



Elephas indicus (PL XL fig. 4). 



Through the kindness of Professor Turner I have been able to examine the feet of a 

 foetal Indian Elephant, which has been preserved in spirit in the stores of the Anatomical 

 Museum of the Edinburgh University for a great number of years. 1 The results I have 

 obtained differ very slightly from those described by Messrs. Miall and Greenwood in 

 their exhaustive paper upon the Anatomy of the Indian Elephant. 2 



In the disposition of its intrinsic muscles the foot of the Elephant is peculiar on 

 account of the absence of the greater number of the plantar adducting and the dorsal 

 abducting muscles. Encased as the digits are in the tough integument and the thick 



1 This specimen was described and figured by Professor Turner in the Jour. Anat. and Phys., July 1881. 



2 J ournal of Anatomy and Physiology, voL xii. pp. 286 and 287. 



