No. 3.]} MUSCLES AND NERVES IN AMIA CALVA. 635 
Terminal buds in Amia are just beginning to appear on the 
outer surface of the head in 10 mm. larvae. Their distribution 
is shown in Figs. 4 and 5 of my earlier work; Figs. 6 and 7 
showing a slightly more advanced condition. It will be noticed 
that the organs are, in many places, arranged in lines, and that 
well-marked lines are found on each side of the line of the supra- 
orbital canal line, and on one side only of the infraorbital line, 
that is, on its dorsal side, between it and the eye. Other lines 
of organs are found on the maxilla and at its base, below and 
in front of the line of the infraorbital canal. If, now, the rami 
-ophthalmicus superficialis and maxillaris superior trigemini of 
the adult be considered, it is seen that branches arise from the 
ophthalmicus trigemini in pairs, one branch issuing on the 
median side and one on the lateral side of the ophthalmicus 
facialis ; that on the maxillaris superior all the small branches 
below and behind the eye, excepting only the accessory branch 
‘““r.c,”’ issue on the dorsal or median side of the buccalis, and that 
the one large branch, the one destined to supply the maxilla, 
issues on the ventral side of that nerve. The branches of these 
two trigeminal nerves in the adult thus have the same relations 
to the nerves innervating the canal lines that the lines of termi- 
nal buds in 10 mm. larvae have to the lines of the canals. As 
the trigeminal nerves both lie deeper than the corresponding 
facial nerves, and as their branches issue on both sides of the 
latter, it is evident that*they must first have been split off from 
the ectoderm before the facial nerves, split off apparently from 
exactly the same lines, could have arisen. This is exactly what 
Platt finds for the ophthalmic nerves in Necturnus (No. 91, p. 
949). 
The branch of the trigeminus that goes to the maxilla in 
Amia is the branch which, according to Pollard, furnishes the 
sensory supply of the maxillary tentacle in siluroids, and a part 
of that of the coronoid tentacle. Where there is but a single 
tentacle at the angle of the mouth, the maxillo-coronoid tentacle, 
the larger part of its sensory supply is from this same nerve. 
The nerve is called by him the ramus maxillaris. His ramus 
premaxillaris is represented in Amia by those branches of the 
maxillary nerve of Amia that continue forward toward the pre- 
