786 



MAMMALIAN ANATOMY 



formed like a toe of the opposite foot ; and the third toe is either 

 indifferent or almost normal (Fig. 609, right foot). A modifi- 

 cation of this type has been described in which all four outer 

 digits were normal, but the metatarsals of the two inner digits 

 were coalesced at their proximal and distal ends, and supported 

 three amorphous phalanges with three claws, two large and one 

 rudimentary. 

 This type of polydactylous foot appears most frequently. 



FIG. 609. 



Ectocuneiform. 

 Cuboid. 



) Representing 

 > Mesocuneiform and 

 ) Entocuneiform. 



Ectocuneiform. 



Cuboid. 



RIGHT FOOT LEFT FOOT. 



SUPERNUMERARY DIGITS OF ONE CAT. 



HUMAN FOOT. 



The human foot (Figs. 610, 611) differs from the cat's foot princi- 

 pally by its relatively shorter and broader form, and by the possession 

 of a very large first digit or great toe, which consists of a metatarsal 

 bone and two phalanges. The other changes in the foot are the result 

 of the weight it sustains by being placed flat on the ground. 



The tarsus is relatively long. The seven tarsal bones closely re- 

 semble in shape and in the areas of articulation the tarsal bones of 

 the cat. The entocuneiform, which supports the great toe, is relatively 

 much larger, and the ectocuneiform is relatively much smaller. 



The astragalus is cuboidal ; its neck is not so well marked, and 



