No. 3.] MUSCLES AND NERVES IN AMIA CALVA. 637 
larvae (No. 3, Fig. 12) the buds have increased at the upper end 
of the operculum, are beginning to appear along the branchio- 
stegal rays, spreading backward from the mandible, and are 
also found above organ 17 infraorbital. 
The buds on the cheek as they first appear in larvae have 
approximately the position and direction of the accessory trige- 
minal nerves in the adult, and these accessory nerves have the 
same relation to the branches of the buccalis, behind the eye, 
that those branches of the maxillaris superior, that arise below 
the eye, have to the buccal branches there. These branches 
seem, therefore, to innervate the terminal buds, and in that 
case they would belong to the fasciculus communis root, and 
not to the general cutaneous root of the trigeminus, as Strong 
finds in Rana. The only other supposition is that the buds on 
the cheek are innervated by the mandibularis internus facialis, 
which seems improbable. 
The buds on the mandible lie in the region supplied by 
the anterior branches of branch 4 of the maxillaris inferior 
trigemini. These branches have the course and position of 
the ramus coronoideus of Pollard, a nerve which, in siluroids, 
innervates part of the sense organs of the coronoid tentacle. 
Accompanying this nerve in Silurus glanis I find a large branch 
of the mandibularis facialis. This nerve in Silurus may be a 
branch corresponding to the one which in Amia innervates the 
mandibular line of pit organs, and in Gadus innervates a man- 
dibular line of the slit-like organs peculiar to that fish. If this 
be the case, pit organs or other organs of a similar character 
should be found in Silurus in the region innervated by the 
nerve. Of this I have not yet attempted any investigation. 
The nerve corresponds almost exactly to a branch of the 
facialis in Carcharinus. 
The buds above organ 17 infraorbital, and hence posterior to 
the middle pit line of the head, are innervated either by the 
first pair of branches from the ophthalmicus superficialis trige- 
mini, or by the branches of the first vagus that anastomose 
with that nerve. The branch of the glossopharyngeus that 
innervates the pit organs of the middle head line lies super- 
ficial to the united trigeminal and vagus nerves, as it should if 
