596 
F. H. EDGEWORTH. 
chloroform. The muscles and nerves, both on the cut and 
uncut (normal) side, were then dissected out. Sections of the 
muscles were stained by van Giesen’s method. The nerves 
were stained by osmic acid and examined in transverse section. 
All the masticatory muscles, including the tensor veli 
palatini and tensor tympani, together with the mylohyoid and 
anterior belly of the digastric, showed evidence of degenera- 
tion — loss of transverse striation, increase in the number of 
nuclei, and proliferation of the interstitial tissue. 
The tensor veli palatini and tensor tympani are, conse- 
quently, innervated by the fifth cranial nerve, and belong to 
the group of masticatory muscles. This conclusion agrees 
with that obtained by investigation of their development. 
The Anlage of the masticatory muscles divides into an internal 
lamina, giving rise to the internal pterygoid, pterygo-tym- 
panicus or tensor veli palatini, and tensor tympani ; and an 
external lamina, giving rise to the external pterygoid, temporal 
and masseter. 
It may be added that no degenerative changes were found 
in the levator veli palatini — a muscle which is developed from 
the pharyngeal musculature, and is innervated by a branch of 
the pharyngeal plexus (Cords) from the vaso-accessorius 
(Beevor and Horsley). 
In the muscle-nerves on the uncut (normal) side medullated 
fibres of all sizes were present from a diameter of under 4 (x up 
to a certain maximum. This maximum was 12'8 fx in the nerves 
passing to the tensor veli palatini, internal pterygoid, external 
pterygoid, temporal, masseter, and anterior belly of digastric ; 
1T4 fx in the nerve to the mylohyoid, and 5’6 q in the nerve to 
the tensor tympani. 
Medullated nerve-fibres were also present in the muscle 
nerves on the cut side, of all diameters from one under 4 fx up 
to the same maxima as in the corresponding nerves on the 
uncut side, e.g. it was 12'8 q in the branch of the mylohyoid 
nerve to the anterior belly of the digastric and lT4ju in the 
branch to the mylohyoid muscle. The number of medullated 
nerve-fibres in the branches on the cut side formed from 35 to 
