26 SCIENCE SKETCHES. 



One of the most simply beautiful of all fishes is 

 the Green-sided Darter {^Diplesion blennioides Rafi- 

 nesque). He is not, like the PoecilicJithys, an ani- 

 mated rainbow; but he has the beauty of green 

 grass, wild violets, and mossy logs. As we watch 

 him in the water, with his bright blended colors 

 and gentle ways, once more, with Old Izaak, '' we 

 sit on cowslip banks, hear the birds sing, and pos- 

 sess ourselves in as much quietness as the silent 

 silver streams which we see glide so quietly by us." 

 During the ordinary business of the year Diple- 

 sio7t, like most sensible fishes and men, dresses 

 plainly. It is not easy to get time for contempla- 

 tion when the streams are low and food is scarce. 

 Besides, a plain coat may ward off danger as well 

 as facilitate attack. At all times, however, he may 

 be known by these marks : the fins are all large ; 

 the back is covered with zigzag markings, while 

 on the lower part of the sides are eight or nine 

 w-shaped olive spots. These are more or less con- 

 nected above, and sometimes form a wavy line. 

 The eyes are prominent ; the snout is very short 

 and rounded ; while the little inferior mouth is 

 puckered up as if for saying " prunes and prisms, 

 prunes and prisms." But when the first bluebirds 

 give warning by their shivering and bodiless notes 

 that spring is coming, then Diplcsion puts on his 

 wedding-clothes, and becomes in fact the green- 

 sided darter. The dorsal fins become of a bright 

 grass-green, with a scarlet band at the base of each ; 

 the broad anal has a tinge of the deepest emerald ; 

 while every spot and line upon the side has turned 

 from an undefined olive to a deep rich green, such 



