A FAMILY OF WATER KINGS. 443 



appeal must not itself be submitted to investigation and state- 

 ment to theory strikes me as decidedly na'ive. 



Here as elsewhere our greatest need is to make our theories 

 submit to the test of practice, to experimental verification, and, 

 at the same time, make our practice scientific make it the em- 

 bodiment of the most reasonable ideas we can reach. The ulti- 

 mate test of the efiicacy of any movement or method is the equal 

 and continuous hold which it keeps upon both sides of this truth. 



A FAMILY OF WATER KINGS. 



By Peof. CLAEENCE M. WEED. 



THERE is, perhaps, no way in which one can obtain a more- 

 vivid idea of the intensity of the struggle for existence among 

 organic beings than by the study of the inhabitants of a fresh- 

 water pond of long standing. Every inch of space in such a situ- 

 ation is teeming with life, both animal and vegetable, and the 

 chief delight of most of the animals present is to wage a ceaseless 

 warfare upon their weaker fellows. It is an aquatic rendition of 

 Edwin Arnold's aerial drama : 



"... Then mai'ked lie, too, 

 How lizard fed on ant, and snake on liiin, 

 And kite on both ; and how the fish-hawk robbed 

 The lish-tiger of that which it had seized ; 

 The shrike chasinf? the biilbul, which did hunt 

 The jeweled butterflies ; till everywhere 

 Each slew a slayer and in turn was slain, 

 Life living upon death. So the fair show 

 Veiled one vast, savage, grim conspiracy 

 Of mutual murder, from the worm to man. 

 Who himself kills his fellow." 



The largest insects occurring in our fresh-water ponds are the 

 giant water bugs a family of peculiar creatures, armed with im- 

 mense front legs fitted for grasping and clasping their victims, 

 and a piercing, dagger-like beak which serves both to strike the 

 prey and as a sucking tube to extract its juices, and which also 

 appears to be provided with poison glands which make more sure 

 the effect of every thrust. 



Three species of these bugs occur in the Northern United 

 States. Two of them are very large and closely resemble each 

 other ; the third is much smaller, less than half the size of the 

 others. The commoner of the larger ones in the more northern 

 States is represented natural size in Fig. 1. It is called by ento- 

 mologists Belosioma americana, or the American belostoma. It is 



