Kelly — On a Case of Polydactylism. 539 



XL VI. — Oif A Case of Polydactylism. With Plates 36, 37, 38, and 39. 

 By J. E. Kelly, Surgeon to the Jervis-street Hospital, Lecturer 

 on Anatomy and Physiology, &c., &c. 



. [Read 14tli February, 1876.] 



The peculiarities which I have noted were observed in the body of 

 a female, aged about 45 or 50, spare, with good muscular development, 

 and anatomically a virgo intacta. She presented no other external 

 congenital peculiarities besides those represented by the casts ex- 

 hibited, except that she appeared to have had a strabismus, 

 and her incisor teeth projected almost directly forward. The 

 right hip afforded an excellent example of a traumatic dislo- 

 cation of very long standing, with contraction of the acetabulum, 

 atrophy of the head of the femur, remarkable development of liga- 

 mentous tissue anteriorly and inferiorly, and a fissure in the capsular 

 ligament leading to the abnormal receptacle for the head of the femur, 

 which was a smooth cavity under the gluteiis medius muscle (no trace 

 of the gluteus minimus remaining), lined by a glistening membrane 

 which, at that part over the dorsum ilii, covered a very dense layer 

 of fibrous tissue. The psoas muscle was represented by a thin cord of 

 fibrous tissue, but the iliacus and all the other muscles about the joint 

 were well developed. The arterial system was highly developed, and 

 cutaneous vessels, ordinarily imperceptible, attained a remarkable 

 size ; both ulnar arteries were of the aberrant type, and lay over the 

 fascia in their course. Both stylohyoid muscles were absent ; the left 

 renal vein passed posteriorly to the aorta ; the vermiform appendix 

 was about five inches long, and dilated towards its termination. I ob- 

 served no other peculiarities worth noting except those affecting both 

 hands and the left foot. 



The hands were both heptadactylous, and the left foot was an ex- 

 ample of spurious tridactylism, owing to the double syndactylism which 

 had occuiTed. The supernumerary digits were on the radial or volar 

 side of the hands, and may be regarded as cases of reduplication of 

 the poUex. This was indicated by the length and direction of the meta- 

 carpal bones, the muscular attachments, and the vascular and nervous 

 relations. The points of opposition for the digits of the right hand 

 wersfcthree : the apex of the first thumb or the spine ; the dorsal sur- 

 face of the head of the first phalanx of the second thumb ; and the 

 distal extremity of the third thumb. On the left hand there was but 

 one point, the head of the first phalanx of the second thumb, off' 

 which the next (second) phalanx was dislocated. Over these points 

 were developed bursse, and the cuticle was thickened. 



The Bones of the Right Hand : — 



The lower end of the radius normal. The ulna: — On the apex of 

 the styloid process was a facet which articulated with the os trique- 

 trum and the unciform. 



K. I. A. PROC, SEE. II., VOL. II., SCIENCE. 3 H 



