THE EPIBRANCHIAL GANGLIA OF LEPIDOSTEUS 47 
rise to gustatory fibers only. So that in general there is a close 
correspondence between the size of the epibranchial placode and 
the number of gustatory fibers to which the ganglion gives rise 
in the adult. 
A study of Lepidosteus, in addition to furnishing a confirmation 
of the conclusion reached from a study of Ameiurus, shows in 
addition that the placodal ganglia maintain their integrity for 
a long time, although embedded in the general visceral ganglia, 
and that the late appearance of the epibranchial placodes and their 
slow metamorphosis into ganglion cells is closely correlated with 
the retarded appearance of the gustatory organs. This correla- 
tion, when taken in conjunction with the fact that only those 
ganglia having placodal cells give rise to gustatory fibers and in 
proportion to the size of the placodes and that all ganglia having 
epibranchial placodes give rise to gustatory fibers and particularly 
that a ganglion that is apparently exclusively placodal is also 
apparently exclusively gustatory, seems to warrant the assumption 
that placodal ganglia are special visceral ganglia. 
