FAMILY RECORD. 29 



This occurrence of a cripple, the only one in the whole family for 

 six generations, as a result of an intermarriage between one brachy- 

 phalangous individual and his cousin whose father had brachypha- 

 langy, is very remarkable. It suggests the possibility that this cousin 

 was brachyphalangous, genetically heterozygous for the factor, and 

 that this child may have been homozygous for it, receiving one gene 

 from her father and one from her mother. This explanation, if correct, 

 involves the assumption that the character we have studied, the 

 brachyphalangous index, represents only the heterozygous condition, 

 and that the factor, when homozygous, affects the individual in a 

 much more serious way. This conclusion is by no means certain, but 

 is at least strongly suggested by the facts of the case. This point will 

 be more especially discussed later. 



Summing up: Brachyphalangous ll.Sd" C. A. B. H., who showed 

 the B !-type of the malformation, by his first marriage with his cousin 

 17.1 9 F. G. 0., had 2 children, one brachyphalangous and one cripple 

 unable to develop. 



THIRD FAMILY OP IV GENERATION. 



The brachyphalangous 11. 5 c? C. A. B. H. married in 1874 for a 

 second time. This wife (S. M. C. W., Aug. 1, 1843-May 3, 1899) was 

 normal and quite unrelated to him. They had 6 children, 115.3-115.8. 



115.3 cf P. F. G. H. (b. Nov. 16, 1875), mail carrier. A photograph 

 of his hands is given in fig. 1. The indices are quite normal. We 

 mention especially that photographs taken from the inside show that 

 the distance between the two distal grooves in the skin marking the 

 joints is very little shorter in the indices than in the fourth fingers. 

 In brachyphalangous hands of the B-type this distance is generally 

 markedly shorter in the indices. The radiographs prove that the 

 relative lengths of the finger bones are normal, the lengths of II 2 and 

 IV 2 being respectively 25 and 29 mm. on both hands. 



115.3d" P. F. G. H. married J. G. (b. Oct. 10, 1880) who was not 

 related to him and who has normal hands. They have 3 children, 

 1153.1-1153.3 (p. 34). 



115.4cf M. H. (b. Apr. 4, 1870), merchant. A photograph of his 

 hands (fig. 7) shows a very characteristic B !-type brachyphalangy. 

 As in the case of his father's hands, the right brachyphalangous index 

 is bent, while the left is straighter. 



Radiographs are given in fig. 40. In the right hand the short second 

 phalanx of the index remains as a bone the size of a pea and is dis- 

 located in the ulnar direction, as described when speaking of the 

 father's hands. In the left index the second phalanx is seen to be 

 reduced so much in size that its existence might almost be overlooked. 

 Its position is (as on the right hand) in the ulnar part of the joint. 



The other finger bones are normal except the second phalanx of the 

 fifth finger of the right hand, which is thicker and 4 mm. shorter than 



