Charles R. Bardeen 363 
and flexor hallucis longus muscles; in 3, in conjunction with the nerve 
to the flexor hallucis muscle; in one in conjunction with that to the flexor 
digitorum ; in one, in conjunction with that to the popliteus and posterior 
tibial muscles; and in one in conjunction with a nerve to the posterior 
tibial, flexor digitorum and flexor hallucis muscles. 
Nerve to the flexor digitorum longus. Out of 36 instances, in 20 the 
nerve arose independently, in 6 of these by two separate branches; in 
6 instances it arose in conjunction with the nerve to the flexor hallucis 
muscle; in 4 others, in conjunction with this and the distal nerve to the 
soleus. In three instances it arose in conjunction with the nerve to the 
flexor hallucis and that to the tibialis posterior muscle; in one, in con- 
junction with that to the tibialis posterior; in one, in conjunction with 
the distal nerve to the soleus; and in one, with the nerve of the tibialis 
posterior and flexor hallucis and the distal nerve to the soleus. 
Nerve to the flexor hallucis muscle—Out of 85 instances, in 18 the 
nerve arose independently, in two of these by two separate branches. In 
six instances the nerve arose in conjunction with the nerve to the flexor 
digitorum longus muscle; and in 4 other instances, in conjunction with 
this and the distal nerve to the soleus. In three instances it arose in 
conjunction with the distal nerve to the soleus; in three, in conjunction 
with the nerve to the flexor digitorum and tibialis posterior; and in one, 
in conjunction with the distal nerve to the soleus and the nerves to the 
tibialis posterior and flexor digitorum longus. 
4. Development and Innervation of the Muscles Supplied by the Lateral 
Plantar Nerve. 
To this group belong the quadratus planta, the abductor, flexor brevis, 
and opponens digiti quinti, the interossei, and the three lateral lumbrical 
muscles. 
M. quadratus plante.—The anlage of this muscle appears in a 14 mm. 
embryo (Plate IX, Fig. 4) medial to the lateral plantar nerve as this 
curves about the tuber calcanei. Schomburg, oo, describes it in about 
the same position, but fused with the flexor hallucis longus at a nearly 
corresponding stage. In the 14 mm. embryo the nerve to the muscle is 
not distinct but in a 20 mm. embryo (Plate IX, Fig. 6) a well marked 
nerve enters its superficial surface from the deep surface of the lateral 
plantar nerve as this crosses the muscle. The muscle can readily be 
traced from the calcaneus to the deep surface of the plantar aponeurosis. 
In the adult the nerve to the quadratus plente arises from the lateral 
plantar nerve near the medial margin of the muscle and crosses on or 
