GFOHNNY DARTERS. 23 
with a stick. These peculiarities of temperament 
are important factors in the problem of life; and 
from such differences under varying conditions, 
may have resulted forms which we now designate 
as different species. 
But we must leave these general questions for 
the present, and tell the story of the Johnny Dart- 
ers that live in our aquarium.! 
First of these in size and therefore in dignity 
comes the Log Perch or Hog-fish (Percina ca- 
prodes Rafinesque). This is the giant of the 
family,—the most of a fish, and therefore the 
least of a darter. It may be readily known by its 
zebra-like colors. Its hue is pale olive, — silvery 
below, darker above. On this ground-color are 
about fifteen black vertical bars or incomplete 
rings, alternating with as many shorter bars which 
reach only half-way down the side. The hind- 
most bar forms a mere spot on the base of the 
tail, and there are many dots and speckles on the 
fins. The body is long and slender, spindle-shaped, 
and firm and wiry to the touch. The head is flat 
on top, and tapers into a flat-pointed snout which is 
squared off at the end like the snout of a pig; and 
this resemblance is heightened by the form of the 
small mouth underneath it. From this pig-like 
snout has come the scientific name caprodes. 
This is a translation of the older name of “ hog- 
fish,” which Rafinesque heard applied to it in his 
time, and which is still used in the same regions. 
Percina reaches a length of six or eight inches, 
1 At Indianapolis, Indiana. All the species here mentioned, and 
some others, are found in the White River, near Indianapolis. 
