ANIMAL LOCOMOTION. 



85 



omists are most familiar. Aeby* describes a similar arrange- 

 ment in the foot of the gorilla. 



It was reasonable to infer from these data that the disposition 

 of the calcaneum to transfer the strain transmitted to it across the 

 foot to the scaphoid would characterize the mammalian foot. 



A careful examination of the tarsus lias not warranted the in- 

 ference. As shown by Leboucq, the arrangement exists in the 

 embryo, but it is not maintained as a rule in the adult, nor is it 

 seen in the phylogeny of the group. 



Fig. 2. 



Fig. 3. 



Fig. 4. 



Fig. 2. — Di;igiam of the relation of the astragahis (A), the calcaneum (C.\), the scaphoid 

 bone (S), and the cuboid bone (Cb) in the foot of mammals. 



Fig. 3. — Diagram to exhibit the disposition for the astragalus to form a junction with 

 the cuboid bone. (Letters as in Fig. 2.) 



Fig. 4. — Diagram to exliibit a disposition for the calcaneum to form a junction with 

 the scaphoid bone. (Letters as in Fig. 2.) 



The statement of Kowalevnsky is accepted, that the earlier 

 forms of mammals exhibit lines of support which correspond to 

 the arrangement of the bones of the leg. (See Fig. 2.) But in the 

 animals now living, the lines of the bones of the carpus and tarsus 

 do not as a rule show such independence. The bones of the tar- 

 sus are almost invariably more or less displaced. In the tapir 

 and the rhinoceros, which are the best living examples of related 

 forms to the earlier forms, the acquired support from adjusting 

 rows is as exact as in any of the numerous recent specialized 

 forms which at present inhabit the earth. 



So far as examined, the calcaneum articulates with the scaphoid 

 bone in the following genera only: 

 Homo, 



Troglodytes, 



Equus (variable; sometimes 

 astragalo-cuboid). 



Dipus, 

 Coelogenys, 

 Erethizon (variable). 



*Morph. Jahrbuch, iv., 1878. 



