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Charles R. Bardeen 
origin from the 23d spinal nerve the distribution is extensive in most of 
the instances studied. 
The inguinal and genital nerves show relatively much less extensive 
variation in distribution. My data concerning the variation in their dis- 
tribution as well as that of the iliac nerves are less accurate than those 
of the lumbo-inguinal so that the latter nerve may serve as an example 
of variation in the distribution of the border nerves. 
II. CUTANEOUS NERVES OF THE FEMORAL GROUP. 
a. Development. 
By “cutaneous nerves of the femoral group” may be designated the 
lateral (external) cutaneous nerve of the thigh and the cutaneous nerves 
which usually spring directly from the femoral nerve. These nerves are 
all directed at first toward the anterior margin of the limb-bud. Figs. 1-3, 
Plate III, show their situation in an embryo of 11 mm. length. In Plate 
IV, Figs. 1 and 2, and Plate VI, Figs. 1, their position is shown in an 
embryo of 14 mm. 
In this latter embryo (CXLIV) the lateral cutaneous nerve arises from 
the main trunk of the femoral, passes outwards through the anlage of 
the psoas muscle and approaches the skin near the junction of the anterior 
“margin of the limb with the thigh. Several anterior and medial cutaneous 
nerves arise from the femoral nerve. The most proximal of these ap- 
proaches the surface of the limb-bud somewhat more distally than the 
lateral cutaneous. A branch may likewise be followed through the anlage 
of the sartorius muscle and two through the septal tissue which divides 
the sartorius from the adductor group of muscles. The saphenous nerve 
passes between the anlages of the tendons of the sartorius and gracilis 
muscles to reach the subcutaneous tissue near the knee (Plate VI, 
Big. 1). 
In an older embryo, XXII, length 20 mm. (Plate V, Figs. 1 and 2, 
and Plate VI, Fig. 2), the further growth of the nerves just men- 
tioned may be followed. The lateral cutaneous nerve has spread out in 
several branches toward the lateral surface of the thigh. The anterior 
and medial cutaneous branches have spread out over the antero-medial, 
surface of the thigh, while the saphenous nerve has continued its growth 
toward the ankle. During the ventro-posterior rotation of the hip the 
lateral cutaneous nerve has been caught near the anterior superior spine 
of the ium. 
The further growth of these nerves to reach the conditions character- 
istic of the adult may easily be deduced by comparing Plate VI, Fig. 2. 
