chap, xiii.] syndactylism: ox. 385 



borne by the normal metacarpal of the right fore foot were ab- 

 normal, inasmuch as the second and third phalanges were united 

 together. The first pair of phalanges were separate, but their outer 

 ends were modified so as to articulate with the single second 

 phalanx. The distal (third) phalanx bore a groove indicating its 

 double origin, but the second phalanx was without any such groove, 

 and was to all appearance a single structure. 



The left fore foot also bore an outer and an inner supernumerary 

 metacarpal, but in this case it was the inner supernumerary meta- 

 carpal which attained the greatest size. This inner metacarpal 

 bore two small phalangeal bones, while the outer extra metacarpal 

 was more rudimentary and had no phalanges. The phalanges of 

 the two normal toes were separate in the left foot, but though the 

 bones were of the ordinary formation the two toes were enclosed 

 in a common hoof. Boas, J. E. V., Morph. Jahrb., 1890, p. 530, 



figs- 



Boas also states that in the museum of the Agricultural 

 School of Copenhagen are several instances of united toes in the 

 fore foot of the Ox, and that in all these specimens the outer 

 metacarpals (II and V) are larger than they are in normal 

 specimens, but are not so much developed as in the case just 

 described. Boas, I.e. 

 578. A case [sc. Ox (?)] is also mentioned in which the two normal 

 toes of the hind foot were united, and the median and distal parts 

 of the metatarsals II and V were developed, though they are 

 absent in the normal form. Boas, I.e. 



*579. Calf having the digits of each foot united and bearing a single 

 hoof. The carpus and tarsus were not seen. Fore foot. The chief 

 digits, III and IV, were completely united in the fore limbs and bore 

 a single hoof, but, in addition to this variation, the metacarpals of the 

 lateral digits, II and V, were developed and ossified. The length of 

 metacarpal II was 9 cm. and its thickness at the proximal end was 

 T5 cm. Metacarpal Y had a length of 8 cm. and a maximum thick- 

 ness of 1*3 cm. at the proximal end. The metacarpal of the united 

 digits, III and IV, measured 13 cm. in length. The metacarpal V 

 was slightly bifid at its distal extremity, and here presented two 

 articular surfaces. With the internal of these there articulated a bone 

 measuring 2 cm. by 0-5 cm., and attached by fibrous tissue to the end 

 of this bone there was a cartilaginous nodule. The external end of 

 metacarpal V bore a rod-like piece of cartilage, 1 cm. in length. This 

 and the cartilaginous nodule of the other part of the digit together 

 formed the basis of one of the accessory hoofs (ergots), but the horny 

 covering itself was divided by a deep cleft into two imperfectly separate 

 parts. To the metacarpal of II was loosely articulated a bone 2*5 cm. 

 in length, to which a nodule of cartilage was attached. The end of this 

 digit was covered by an accessory hoof, which was imperfectly double 

 like that of V and contained a second cartilaginous nodule, which was 

 distinct from the first and was not supported by any proximal bone. 

 The union between the digits III and IV was complete, and the re- 



b. 25 



