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



of the Sheep, we conclude from the four fatty rings which are seen in its substance on 

 transverse section that they are the same as in the Ox, viz., (l) the two heads of the flexor 

 brevis medii, and (2) the two heads of the flexor brevis annularis. 



Camelus bactrianus (Camel). 



The foot I examined was that of a very young specimen. The suspensory ligament 

 presents the same attachments as in the case of the Sheep. It gives off no slips to the 

 perforatus tendon as in the Ox, and inferiorly it is very much flattened from before 

 backwards. Unfortunately the pes had been injected with gelatine and carmine before it 

 came into my possession, so that all the minute blood-vessels of the sheath of the 

 ligament were full. It was therefore impossible to make out with certainty whether 

 any muscular fibres were present on the surface. From the appearance presented, 

 however, by transverse sections when examined by means of the microscope I am inclined 

 to think that the conversion of the two flexores breves into ligamentous tissue is in this 

 case complete. The Ox, the Sheep, and the Camel, therefore, illustrate very well three 

 distinct stages in the metamorphosis. 



The suspensory ligament of the Elk also appears to contain a considerable quantity 

 of muscular tissue in its constitution. 



Professor Morrison Watson, and Dr. A. H. Young in their paper upon this animal (On 

 the Anatomy of the Elk, Alces malchis, Linnean Society's Journal, Zoology, vol. xiv.) 

 give the following account of the ligaments : — -The interossei " are represented almost 

 entirely by a ligament corresponding to the suspensory ligament of the fetlock in the 

 Horse. It consists of a stout musculo-tendinous band, which extends along the whole 

 length of the metatarsus. The muscular portion does not appear to be arranged in any 

 definite manner. Above the metatarso-phalangeal articulation the band divides into 

 three portions, a central and two lateral ; the central portion, after being connected to 

 the sesamoid bones in this region, is inserted into the bases of the first phalanges of 

 the two anterior toes ; the lateral portions pass one along the outer, and the other 

 along the inner, side of the metatarso-phalangeal joints to terminate on the dorsal 

 aspect of the second phalanges of the anterior toes, by uniting with the extensor 

 tendons." 



Sus scrofa (Pig). 



In the Pig the medius and annularis are largely and equally developed. The 

 minimus and the index {i.e., the marginal toes), whilst they are complete as regards 

 the number of their segments, are short in comparison with the two central digits. 

 The hallux is represented merely by an exceedingly minute rudimentary meta- 

 tarsal bone. 



