chap, xiii.] INHERITANCE OF DIGITAL VARIATION. 399 



wise, does very commonly appear in the offspring or kindred of the 

 varying individuals I can add nothing. It should be mentioned that 

 though in families exhibiting digital Variation the forms that the 

 change takes may differ (in some cases widely even among individuals 

 nearly related) yet on the whole the variation, if recurring at all, more 

 often recurs in a like form. This holds good apart from the rarity 

 of the particular form of variation. The facts described by Farge 

 (I.e., infra) are exceptionally interesting in this connexion. In the 

 family described by him duplicity of the thumbs occurred in the 

 paternal grandmother, while the father and three children had their 

 thumbs of the three-phalanged form as in No. 483. This case strikingly 

 illustrates the well-known principle that Meristic variability may 

 appear in the same strain or family under forms morphologically very 

 dissimilar. 



Attention is also called to the circumstance that in the case of the 

 three toes in the ox (No. 558) the descent was wholly through females, 

 and the same was almost certainly true in the polydactyle cats (No. 480). 

 In the case of the syndactyle pigs the evidence of maintenance of the 

 variation in the strain is very clear (No. 584). See also No. 564. 



As regards digital Variation in Man the following are the best 

 genealogical accounts : 



Anderson, Brit. Med. Jour., 1886 (1), p. 1107. Billot, Mem. mid. milit., 1882, 

 p. 371. Boyd-Campbell, Brit. Med. Jour., 1887, p. 154. Fackenheim, Jen. Zts., 

 1888. Fotherbt, Brit. Med. Jour., 1886 (1), p. 975. Furst (see Canst. Jahresb., 1881, 

 p. 283). Harker, Lancet, 1855(2), p. 389. Lucas, Guy's Hosp. Rep., xxv., p. 417. 

 Morand, Mem. Ac. Sci., 1770, p. 140. Muir, Glasg. Med. Jour., 1884. Pott, 

 Jahresb. d. Kinderh., xxi. , p. 392. Potton 1 quoted by Gruber from de Banse, 

 Bull. Soc. d'Anthrop., 1863, iv. p. 616. Struthers, Edin. New Phil. Jour., 1863(2), 

 pp. 87 et seqq. Wolf, Berl. klin. Wochens., 1887, No. 32. Farge, Gaz. hebd. de 

 med. et chir., Ser. 2, n. 1866, p. 61. Case given Lond. Med. Gaz., 1834, p. 65. 



Association of digital Variation with other forms of Abnormality. 



,15, In the great majority of cases of polydactylism the rest of the body 

 is normal, the limb or limbs varying alone. There are however a cer- 

 tain number of examples of polydactylism in association with other 

 abnormalities ; as for instance with phocomely, cyclopia, double uterus, 

 hare-lip, defective dentition, defect of tibia, etc., but there is nothing 

 as yet to indicate any special connexion between these several 

 variations. Diminution in number of digits and syndactylism is on 

 the contrary very often associated with general deformity and with 

 many forms of arrested development. To this no doubt is largely due 

 the fact that cases of ectrodactylism are commonly irregular, whereas 

 polydactylism is generally fairly regular in its manifestations, for 

 numerous cases of diminution in number of digits occur in bodies or 

 in limbs otherwise amorphous. 



1 The notorious case of a village in Isere where the majority of the inhabitants 

 are said to have been polydactyle. Most modern writers on the subject quote this 

 statement but I have never found original authority for the fact. By some it is 

 referred to Devat, Du danger des manages consanguins, 1862, p. 95, but I can find 

 no mention of the facts in that work. 



