REVIEW OF LITERATURE. 11 



It is true, from Drinkwater's investigation, that the main feature 

 is the abortive condition of the ankylosed second row of phalanges 

 in the second to fourth fingers and a brachyphalangy of the first 

 phalanx of the thumb. But Drinkwater's description and radiographs 

 demonstrate that there is a marked variability in the somatic appear- 

 ance of the character. Not only is the typical ankylosis lacking in 

 several hands on one or more fingers and the degree of brachyphalangy 

 conspicuously different in different individuals, but in addition to the 

 malformation of the finger bones a typical brachyphalangy of one 

 or more metacarpal and metatarsal bones occurs in some cases. The 

 distribution of these special types within the family can not be traced 

 from Drinkwater's paper. The author states that the malformation 

 was always exactly symmetrical, even in those cases that show special 

 peculiarities. 



Another case analogous to those of Kummel, Farabee, and Drink- 

 water is recorded by Gubler (1850) and Gruber (1865) who, however, 

 give no information concerning the heredity. 



More numerous than the extreme cases so far considered are those 

 in which the shortening is less pronounced, so that the brachypha- 

 langous bone, in general, more or less clearly retains the shape of a 

 normal bone shortened along the long axis. This type of malformation 

 may affect phalanges alone, metatarsal or metacarpal bones alone, or 

 at the same time bones of both these categories. Machol, in his elab- 

 orate review of the literature (1907), finds that the phalanges are 

 affected in only 21 per cent of his cases, metacarpalia and metatarsalia 

 in 58 per cent, and combinations of both in 21 per cent. But it must 

 be added that his material is very heterogeneous. The shortening may 

 affect many different hand bones, but here, too, a certain predilection 

 seems to rule with regard to the second row of phalanges in the second 

 to fourth fingers. 



As a typical case may be cited JoachimsthaPs Fall 3 (1900), where 

 a mother and one of her daughters showed brachyphalangy of these 

 phalanges. But most representative are Drinkwater's observations 

 (1912-13, 1913-14). In his two families the brachyphalangy affected 

 the second phalanx of the second to fourth fingers and toes. In the 

 toes there was also an ankylosis between the shortened phalanx and 

 the terminal one. Drinkwater's pedigree covers in both cases five 

 generations, and there is a remarkable constancy of the somatic appear- 

 ance of the character. 



A peculiar type of brachyphalangy, restricted to the phalanges 

 only, is the one recorded by Leboucq (1896) and Joachimsthal (1900), 

 where the shortening of different phalanges (especially of the second 

 row) is combined with hyperphalangy, the index or the middle finger 

 consisting of four phalanges, some of which are brachyphalangous. 

 Joachimsthal describes this type in three members of the same family 

 and in the following generation two individuals were affected in the same 



