212 THE PRACTICAL FISHERMAN. 



witnessed battles of incredible fierceness, in which the combatants have 

 rushed at each other like bulldogs, inflicting wounds of considerable 

 severity. Then, with loving and evident amity, the operation of spawning 

 in all its completeness has proceeded without reference to the vanquished. 

 That an awfully decimating influence is continually at work on the 

 deposited ova exists beyond a doubt, and the presumption is allowable 

 that not more than one- thousandth part of it ever reaches the maturity 

 of a parent fish, having passed unscathed through the perils of incuba 

 tion, alevinage, and hobby-de-hoy-hood, and the vicissitudes of adult 

 life to the period when reproduction commences. There are many causes 

 for this. When lying hidden in the gravel of the stream its living 

 enemies are legion. To say nothing of the ravages sometimes inflicted on 

 the spawning beds by old unfecund cock trout, whose appetites, like the 

 Bengal man-eating tiger, are depraved by age and senility, some of the 

 water animalculae are terrible scourges. Our old friend the Pulex gammari, 

 useful bait as he undoubtedly is for the very fish whose ova he destroys, 

 is perhaps the worst of all. The larvae of various beetles, of the Dytiscus 

 marginalis especially, are very destructive. The larvae of this same Dytis- 

 cus usually yclept "the water devil " will even attack young fish. "The 

 manner," says Dr. Lardner, " in which it deals with its prey shows extra- 

 ordinary intelligence .... when it attracts the notice of the larva the 

 latter accomplishes its object by swimming under its intended victim ; 

 when sufficiently near, turning its head upwards, it seizes its prey between 

 its jointed antennae. Having thus secured it, it stabs it in the belly with 

 its sharp mandibles, so as to disable it, then rises to the surface of the 

 water, and, holding its victim above the water so as to (partially P) 

 prevent its struggling, shakes it as a dog would a rat." 



I have seen this so-called water devil tear open an ovum and delibe- 

 rately proceed to devour its contents, which it did with great apparent 

 gusto in a wonderfully short space of time. The larvae of the family of 

 the Libellulidae, popularly known by the name of horse stingers or dragon 

 flies, are also inveterate destroyers of trout ova. I had one in my posses- 

 sion almost 2in. in length, which, when caught, had completely gorged 

 itself with perch spawn. The lurco, or glutton (the larvae of the naid), 

 may also be placed in the foremost ranks of such enemies of the trout, 

 on all of which Salmo fario revenges himself by devouring them during 

 some part of their existence for his own maintenance, which reminds 

 one of Hamlet's quaint conceit ("Hamlet," act iv., scene 1) : "A man 

 may fish with a worm that hath eat of a king, and eat of the fish that 

 hath fed of that worm." 



The young of all the salmonidae are liable to a certain fungoid growth, 

 which is analogous to the salmon plague, and is usually termed the "gill 



