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tiously at a distance, snapping up the fishes that have drifted away, 

 but they soon come closer, and once their appetite is roused, go 

 raging round, and unless checked will even ravenously attack the 

 net, tearing great holes and causing loss of fish as well. Sometimes 

 they become so insensate that they throw themselves out of the 

 water on top of the floating mass, tearing at the enmeshed fish 

 below. Trawlers carry rifles for these brutes, and during each haul 

 the skipper generally accounts for a number, some of them lo to 

 12 feet or more in length. One shot in the head and you see the 

 ugly beast sinking slowly into the green depths, rolling over as it 

 goes. 



We got all the specimens I wanted on that trip, and some un- 

 expected rarities as well. We were due back on a Monday. On the 

 Thursday night the wireless news mentioned fish mortality at 

 'Walvis Bay, maddeningly only a few words, but they were enough 

 for me ; indeed they were as effective as an electric shock. 



On the South-west African coast, mostly in late summer, fishes 

 are sometimes killed in millions, sometimes in such vast numbers 

 as to be a serious menace to health when those thrown ashore 

 begin to decay, and their disposal is a great problem. This whole- 

 sale slaughter is believed to be due partly to volcanic activity and 

 mostly to quantities of sulphuretted hydrogen, released into the 

 sea from bottom deposits. This stinking gas is poisonous to all 

 animal life, but especially to fishes, for it removes dissolved 

 oxygen from the water. 'One man's poison is another man's meat' 

 is a transposition that applies here, for while this is hard on the 

 fish and a great trouble to all who live on that coast, an event of 

 that nature is an ichthyologist's dream, for every kind of fish in 

 the sea is killed, and even though like most things in nature it is 

 extravagant, it gives the scientist an opportunity he could other- 

 wise hardly accomplish by any means himself. While interested 

 people can pick out a few obvious oddities from among the piled 

 masses of dead fish, it is essential that an expert should work 

 through such an accumulation himself, for while the queerest- 

 looking creatures may be merely common and scientifically well- 

 known forms from deep water, an apparently ordinary-looking 

 fish may well be a scientific treasure. 



For many years I had been waiting for an opportunity like this, 

 and here it was and I was much nearer than usual. Despite the 



