JOHNNY DARTERS. 23 



with a stick. These pecuHarities of temperament 

 are important factors in the problem of hfe ; 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. 



