MUSCLES INNERVATED BY THE FIFTH CRANIAL NERVE. 599 
(fig. 8) to take up a position on its antero-median side. Here 
they are joined by a filament from the otic ganglion, contain- 
ing’ a few small medullated fibres. It was not found possible 
to estimate the relative numbers of intact fibres following the 
two paths. 
It follows, from these observations, that in Macacus 
cynomolgus all the muscles which are innervated by the 
fifth cranial nerve receive not only direct medullated nerve- 
fibres from the motor root, but also afferent nerve-fibres 
which originate in the Gasserian ganglion. These ganglion- 
ated afferent nerve-fibres form about one third of the total 
number of the medullated nerve-fibres passing to each 
muscle. They are of all sizes up to the same maximum 
diameters as are found in the corresponding intact branches 
of the opposite side. The ramus medialis and mylohyoid 
branches also receive a few fine medullated fibres fi-oin the 
otic ganglion. 
The proportion of ganglionated affei’eut nerve-fibres found 
in the muscle-branches of the trigeminus is thus closely 
similar to that shown by Sherrington to exist in the branches 
of spinal nerves passing to skeletal muscles. 
Examination, by serial sections, of the mandibular division 
of the fifth nerve in man (figs. 9-20) showed similar results. 
The motor root receives fibres, just below the Gasserian 
ganglion, from the ramus posterior. The fibres of the ramus 
lateralis pass directly from the motor root into the ramus. 
The ramus medialis and the mylohyoid nerve are formed 
from fibres which leave the motor root and pass, some inside, 
some outside the ramus posterior, and then join to form these 
two branches. In some respects the constitution of the 
ramus medialis and of the mylohyoid nerve is even clearer 
than is the case in Macacus, owing to the inner and outer 
fibres of the mylohyoid nerve being situated distinctly more 
proximal — nearer the Gasserian ganglion — than are the inner 
and outer fibres of the ramus medialis, and also owing to the 
separation of the fibres of the ramus posterior into groups. 
Examination by serial sections of the mandibular division 
VOL. 58, PART 4. NEW SERIES. 40 
