144 S. R. DETWILER 
A study of the shoulder region of this individual showed that 
the shoulder muscles were well developed (table 3). . Peripheral 
innervation to these muscles was also found to be complete. The 
shoulder-girdle was almost typical. The procoracoid, however, 
- was poorly developed. The procoracoid is frequently consid- 
erably reduced in size or entirely lacking in the transplanted 
girdle. Experiments hitherto reported (Harrison, 718, and Det- 
wiler, 718) have shown that, when the limb rudiment is trans- 
planted, the procoracoid rudiment may be entirely excluded so 
that its entire development takes place in the old situation. 
Since the girdle lacks the power of qualitative restitution 
(Detwiler, 718), variations, therefore, in its size and completeness 
are the results of a greater or less amount of the respective rudi- 
ments having been included in the transplant, added to, perhaps, 
certain mechanical factors governing its shape as it develops 
in different heterotopic positions. 
In the remaining cases sectioned shoulder-muscle differentiation 
was'on the whole as complete as in case AS5,;, although the 
peripheral innervation was less perfect, a fact that would partly 
account for the restricted function which these cases exhibited 
(table 3). 
Case AS5., (fig. 15), though exhibiting fair movements of the 
forearm, was very defective in shoulder movements. Although 
four segmental nerves contributed to the mnervation of the 
transplanted limb (fig. 12), the shoulder muscles ‘were poorly 
innervated, even though all had undergone complete differentia- 
tion, the following muscles being without nerve supply: m. 
procoraco-humeralis, m. supracoracoideus, m. dorsalis scapulae, 
m. coraco-brachialis longus, and the m. pectoralis (table 3). 
The shoulder-girdle also exhibited some imperfections, the 
suprascapula being short and the procoracoid being entirely 
wanting (table 4). In ‘such a case, incomplete or restricted 
function of the shoulder is clearly a result of defective peripheral 
innervation to its muscles. 
Case AS5.5 showed a distinctly poor nerve supply to both 
shoulder and limb, both of which had undergone complete 
