322 The Nerves and Muscles of the Leg 
thigh into a common trunk there seems normally to be no crossing of 
nerve fibres from one nerve to the other. Branches arising from each 
nerve may be bound for a certain distance into a common trunk provided 
that they occupy contiguous positions in the parent nerve, as indicated 
in the diagram Fig. 6. 
N. peron. prof, N. popliteus. 
‘ ~ N. plant.med. 
N. peron. superf. 
N.semit. 
-distal. branch 
‘\ N. gastroen. 
fs ao - Sapmed. 
N.cut.surae. lat. cag roa 
N.semit 
-t--prox. branch 
. N. biceps. 
cap. breve.- _N. gastroen. 
c&p.lat 
: N. biceps 
/ Cap. long. 
N.tib. posl.- ay “ff 
N. Flex. dig. long: 3 eee 
N. soleus (R.profy ae \ 
N.flex. hal. long’ 
N.cut.Sur.ae. medi 
N. pla nt. lat: 
rGaos 
See text above. 
1 
! \ 
R.M.plant’ 
IV. SUPERIOR GLUTEAL GROUP. 
a. Embryonic Development. — 
1. General Features. 
This group consists of the gluteus medius and minimus muscles, the 
piriformis, and the tensor fasciz late. The last becomes distinct from 
the general muscle mass at a very early stage, the others are closely bound 
together during the earlier stages of differentiation in the anlage. Graf- 
enberg, 04, has described the development of these muscles in man. In 
an embryo of the fifth week he describes a cone-shaped mass of dense 
