RAINBOW-FISH 371 



most alluring of them are the so-called "rainbow 

 fish." They abound in the submerged forests of 

 grass that fringe the water after heavy falls of 

 rain. There they hang, hovering about, curiously 

 investigating all the recesses of the jungle, and every 

 now and then charging at one another in furiously 

 hostile encounters. They are so exceedingly thin 

 as to be almost invisible when looked at from 

 above, but they shine out conspicuously wherever 

 the sun's rays strike in obliquely and light up the 

 brilliant tints of their side scales and the lateral 

 surfaces of their fins. Then they show up, painted 

 in a ground colour of soft greyish yellow, adorned 

 with brown bands, and contrasting with the ruddy 

 hue of the fins, the dorsal and ventral ones bordered 

 behind by a line of shining blue, and the former 

 shaded above, and capped by a sharp black spine, 

 which is at once erected on any excitement or 

 alarm. Swarms of other little fish accompany them, 

 some spotted and barred with brown and red, and 

 others shining so brightly that they look like little 

 sudden flashes of light as they dart hither and 

 thither through the sunlit water. Curious little 

 creatures, too, go gliding about in troops close to 

 the surface, so translucent and quietly coloured 

 that they would readily escape notice were it not 

 for the presence of a luminously white speck on 

 the back of their heads. 



Fish seem to have very little sense of propor- 



