334 MERISTIC VARIATION. [part i. 



supplied the side of the ring linger left unprovided for, but this is 

 uncertain. Assuming this to have been the case, each ulnar nerve 

 supplies the palmar surface of one finger and a half, the median supply- 

 ing the remaining fingers of both hands. Unfortunately no dorsal 

 branches except those mentioned have been preserved." 



Dwight, T., Mem. Boston Soc. of JV. H.. 1892, Vol. iv. No. x. 

 p. 473, Pis. xliii and xliv. 



[This is a case of high significance. We shall come back 

 to it hereafter. Meanwhile it will be noted that in it we meet 

 again the old difficulty so often presented by cases of Meristic 

 Variation. In this fore-arm there is already one true ulna. 

 Internal to it is another bone also formed as an ulna. We 

 may therefore, indeed we must, call it an ulna. But is it 

 an " ulna " ? To answer this we must first answer the question 

 what is an ulna? Similarly, is the second pisiform a "pisiform," 

 or is the second ulnar nerve an c< ulnar " nerve ? These questions 

 force themselves on the mind of anyone who tries to apply the 

 language of orthodox morphology to this case, but to them there is 

 still no answer. Or, rather, the answer is given that an " ulna," a 

 " pisiform " and the like are terms that have no fixed, ideal 

 meaning, symbols of an order that we have set up but which the 

 body does not obey. An " ulna " is a bone that has the form of an 

 ulna, and a " pisiform " is that which has the form of a pisiform. 

 If we try to pass behind this, to seek an inner and faster meaning 

 for these conceptions of the mind, we are attempting that for which 

 Nature gives no warrant : we are casting off from the phenomenal, 

 from the things which appear, and we set forth into the waste of 

 metaphysic] 



493. Boy having abnormalities in the left hand as follows. The four 

 outer fingers II — V are normal in form and proportions. Internal to 

 these is firstly an opposable digit with a single metacarpus and single 

 proximal phalanx but having two distal phalanges side by side webbed 

 together. Internal to this partially double thumb are two digits in 

 series, each with a metacarpal and three phalanges, respectively re- 

 sembling the annularis and minimus of a right hand. Struthers, Edin. 

 New Phil. Jour., 1863 (2), p. 90, PI. n. fig. 5. [Not representing any 

 of the Conditions.] 



494. Male infant, one year and five months, examined alive, having the right hand 

 abnormal, possessing seven digits, arranged in two groups, an ulnar group of 

 four and a radial group of three. Each digit had three phalanges, but the ring 

 and middle fingers of the ulnar group are webbed in the region of the proximal 

 phalanges. The ulnar group seemed to articulate with the carpus in the usual 

 way. The radial group probably formed joints with more than one facet on the 

 trapezium, and possibly also with a surface on the lower end of the radius. It 

 did not seem that the carpal bones were increased in number, for the right wrist 

 had the same circumferential measurement as the left, which was normal. The 

 lower end of the ulna did not seem to articulate normally with the carpus. The 

 elbow was also abnormal, and it seemed "as if the ulna were dislocated inwards." 

 Ballantyne, J. W., Edin. Med. Jour., 1893, cdli. p. 623, fig. [Possibly this 

 condition approached to that found in the last cases.] 



