368 MERISTIC VARIATION. [part i. 



Wehenkel, I. c, p. 15, mentions a similar specimen in the Museum of the 

 Veterinary School at Berlin described by Gurlt, Mag. f. gesam. Thierh., 1870, p. 

 297 [not seen, W. B.]. 



(3) Three digits [1 the digits II and IV being both developed]. 



Examples of this variation are alluded to by many authors but I 

 know of no anatomical description. The following are all very im- 

 perfectly described. 



541. Foal (foetus): left manus having three sub-equal digits; right 

 manus two digits and rudiments of a third more developed than usual. 

 Hind feet normal. Geoffroy St Hilaire, Ann. Sci. Nat., xi. 1827, 

 p. 224. 



Similar case, Bredin, Froriep , s Notizen, xvm. p. 202. 



542. Horse from Texas, having extra digit on inside of each manus, 

 and an extra digit both on the outside and on the inside of each pes 

 [external view only]. Marsh, Am. Jour. Sci., xliii. 1892, p. 344, 



fig- ~- 



543. Horse with both splint-bones bearing digits in each foot. Franck, 

 Handb. d. Anat., Stuttg., 1883, p. 228. 



(4) Two digits ; the digits II and IV both developed, III aborted wholly or in 

 part. 



Mention of these cases must be made in illustration of the possibilities of 

 Meristic Variation, but the parts were in all three instances so misshapen that the 

 animals could not have walked. 



544. Foal having two toes on each foot, the developed toes belonging to the metacar- 

 pals and metatarsals II and IV, while the normally large III was not developed at 

 all in the fore feet and was in the hind feet represented by a wedge of bone only. 



Hind feet. Left. Bones of leg and tarsus said to have been normal. Metatarsal 

 III represented by a wedge of bone fixed between the greatly developed metatarsals 



II and IV. The wedge-like bone 5 cm. wide at upper end, having usual tarsal rela- 

 tions. Its length about the same as its width. Laterally it is united to the 

 metatarsals II and IV which curved round it till they met, and then curve away 

 from each other again. Each was about 20 cm. long and bears a misshapen digit 

 consisting of a proximal phalanx and a hoof-bearing distal phalanx. A small 

 nodule of bone attached to the proximal phalanx may or may not represent part of 

 a middle phalanx. Bight. Very similar to left, but the wedge-like III was rather 

 broader — [for details see original]. 



Fore feet. More misshapen and less symmetrical than hind feet : metacarpal 



III not developed at all. The metacarpals II and IV curved towards each other and 

 crossed, giving an unnatural appearance to the feet. Eight foot. Cuneiform and lunar 

 united, and upon the surface of the bone formed by their union there was a groove 

 occupied by two parts of the tendon of the anterior extensor metacarpi passing to 

 mcp. II and IV respectively. Pisiform and scaphoid normal [this is not clear from 

 the figure]. Magnum absent. Unciform and trapezoid abnormal only in respect 

 of their relations, for whereas they should articulate with the magnum they do not 

 do so, for both magnum and mcp. Ill are not represented. Metacarpal II was 

 11 cm. long, mcp. IV being 19 cm. long. Each bore a digit with a hoof; the digit 



IV having a proximal and a distal phalanx connected by a fibrous cord instead of a 

 middle phalanx. The digit II had a rudimentary distal phalanx only. Left foot 

 like the right, but with the mcp. and digit II more fully developed. [Muscles fully 

 described. It may perhaps be thought that there is not sufficient proof that the 

 developed digits are actually those normally represented by the splint-bones II and 

 IV, but the condition of the hind feet is practically conclusive that this is the right 

 interpretation.] Wehenkel, La Poly dacty lie chez les Solipedes, from J. de la soc. r. 

 des sci. vied, de Bruxelles, 1872, Plate. 



545. Foal, in which the right anterior leg possessed two metacarpals and digits. 



The radius, ulna and proximal series of carpal bones were normal. In the 

 distal series only two bones were present, viz., an inner bone corresponding to the 

 trapezoid, and a magnum. There was no separate bone corresponding to the 



