On the distribution of tbc cutaneous nerves etc. 299 



the result is shown in figure 1. As the nerves were dissected in 

 connection with the skin it has been thought better to represent them 

 in the drawing in this way rather than to show them in relation to 

 the fascia and tendons, as is the more usual practice. In determining 

 the exact positions of the various branches, the following three points 

 were observed 1) the folds corresponding to the metacarpo-phalangeal 

 and inter- phalangeal articulations; 2) the clefts between the fingers; 



3) the usual position of the" larger branches as determined from hands 

 dissected in the ordinary way. To insure accuracy, pins were thrust 

 through the centre of each of the skin-folds. The nerves were at first 

 drawn as they appeared in the dissection, and afterwards reversed 

 and transferred on to a drawing made from the hand of another sub- 

 ject, which was selected for the purpose on account of its similarity 

 to the one in which the nerves were dissected. The following points 

 will be observed : 1) The dorsal branches of the ulnar and radial 

 nerves intercross for the space of three fingers ; the basal parts of 

 the index, middle and ring fingers and a considerable part of the skin 

 of the dorsum of the hand are thus shown to have a double nerve- 

 supply. 2) The smaller twigs always cross on a plane superficial to 

 the larger branches. 3) The communications or anastomoses are in- 

 considerable (in this case), while the nerves freely cross one another. 



4) Speaking generally, the radial nerve retreats for the space of one 

 joint as it advances from the radial to the ulnar side and the ulnar 

 behaves in a similar manner in its course from the ulnar to the radial 

 side; — thus the radial nerve reaches the ungual phalanx of the 

 thumb, the distal inter-phalangeal joint of the index finger, the proxi- 

 mal inter -phalangeal articulation of the middle and the metacarpo- 

 phalangeal joint of the ring finger. The dorsal branch of the ulnar 

 supplies the skin about the nail of the little finger and gradually be- 

 comes more and more proximal in its distribution until it reaches the 

 index finger. 



The advantages of the method employed are obvious. As the 

 ends of the nerves are fixed in the skin, they are maintained in po- 

 sition and also the fine twigs are preserved which would inevitably be 

 removed in skinning the subject in the ordinary way. This mode of 

 tracing cutaneous nerves has been often employed and it appears to 



