364 William Mackenzie : 



Agouti {Dasyprocta). 



Here we obtain marked evidences of the disappearing Fibula, 

 which has assumed a thin almost transparent cartilaginous 

 character with a transparent interosseous membrane. At the 

 upper end no true articulation even with the Tibia is seen, it 

 being retained in position by fibrous bands. It is closely- 

 attached to the Tibia below and takes only a very slight part 

 in the formation of the ankle-joint bj^ articulating with the 

 small outer facet on the astragalus. 



Buffalo (Bulhilus). 



A groove is seen on the lower articular face of the Tibia re- 

 presenting the original separation of the Fibula. The only 

 representation of the Fibula is a thick fibrous band from the 

 Outer T'uberosity of the Tibia to the junction of the upper and 

 middle thirds of that bone. 



Cat {Fe/is do Hies tied). 



This animal is able to spring and can broaden his base when 

 sitting by resting on the whole foot. Hex-e we get a slender 

 roimded Fibula tightly attached, especially below to the Tibia. 

 This rotundity shows the absence of necessary muscular pull ; 

 the lowest i-atio of area to volume is found in the spherical 

 form and for muscular attachment we require area — i.e., 

 surface. It articulates above with the Outer Tuberosity of the 

 Tibia and below enters slightly into the formation of the ankle- 

 joint through the outer facet of the Astragalus. 



Baboon. 



Here Ave have a contrast with the Lemur. There is a distinct 

 separated Hallux, but approaching the Anthropoid type. The 

 formation of the ankle-joint with its deep socket and having 

 both Malleoli projecting well down laterally is opposed to 

 lateral movement. The Tibia and Fibula are well bound to- 

 gether and there is little elasticity present. In the Lemur the 

 Fibula articulates with the upper surface of the Astragalus. 



