368 M ERISTIC VARIATION. [PART i. 



V\'rm:NKi:i.. /. c.. p. L5. mentions a similar specimen in the Museum ot tin 

 Veti-iinarv Srlin.,1 at Berlin described by GCRLT, Mag. f. gesam. Thinrh., 1870. p. 

 -".17 [not seen, W. B.]. 



(3) Three digits [? the diyits II and IV lining both developed]. 



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

 kno\v of no anatomical description. The following are all very im- 

 pert'''<-t ly described. 



541. Foal (foetus): left manus having tliree sub-equal digits; ri^ln 

 manii> two digits and rudiments oi' a third more developed than usual. 

 Hind feet normal. GEOFFROY ST HILAIRE, Ann. Sci. Nat., xi. 1827, 



p. L'24. 



Similar case, BREDix, Froriep's Notizen, xvm. p. 202. 



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

 and an extra digit l>oth on the outside and on the inside of each pes 

 [external view only]. MARSH, Am. Jour, tici., XLIII. 1892, p. 34-1, 



." I-.'!. Horse with both splint-bones bearing digits in each foot. FRANCE, 

 II, < i, ,11,. <l. An, it., Stuttg., 1883, p. 228. 



(4) Tiro till/it* ; tin- diyitii II and IV both developed, III aborted wholly or in 

 part. 



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

 Mi ristic 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. 



Hindft'tt. I./ ft. 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 20cm. long and bears a misshapen digit 

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

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

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

 broader [for details see original]. 



For, 1 fi'i-t. 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. Ri<iht foot. Cuneiform and lunar 

 united, and upon the surface of the bone formed by tlreir 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. Metacarpai II wa- 

 ll cm. long, mcp. IV being I'.tcm. 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 ;he 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 

 ili '\ eloped digits are actually those normally represented by the splint-bones II and 

 IV. hut tin eoii.liiion of the hind feet is practically conclusive that this is the right 

 interpretation.] VvV.in \KI i.. /../ /w// ( /,/, /////, </ : /,.- x, ///;,,, /,.-;, from /. de la soc. r. 

 di-x .-(/. uti'd. (/< /;/i/.r,//,.v. is;-.*. Plate. 



54"). ' oal, in \\liich thr right anterior leg possessed two metacarpals and digits. 



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

 li-tal series only tico bones were present, viz.. an inner bone corresponding to the 

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



