whale-shark, but it is also very inclined to idle at the surface, thus deserving its name 

 " basking-shark " — the " shark that sunbathes ". It occurs mainly in arctic waters and also in 

 the north and south temperate zones. It is particularly abundant around Iceland, off the west 

 coast of Ireland (who does not recall the famous film " Man of Aran "?) and it is equally well 

 known off Breton coasts. There is a fairly active fishery for it. Finally, to complete its analo- 

 gous features with those of the whale-shark, it also feeds on plankton and is quite harmless. 



Harmless... this word has been used twice concerning two sharks, when there are probably 

 no other creatures in the world with such a bad reputation as sharks. Concerning these two,, 

 however, there is no possible doubt. The whale-shark or the basking-shark have never deliber- 

 ately attacked a man. Their mild dispositions are well known. But there are others... 



Human flesh is certainly not the usual diet of sharks. Yet the moment we leave the great 

 plankton-eating sharks we come up against carnivorous species with formidable, often sharp- 

 edged, teeth arming their jaws — fishes that are not always particular in choosing their prey. 

 Some of them are inclined to swallow anything, whether edible or not, within their reach, the 

 stomach contents being a real collection of odds and ends : kegs of nails, a tom-tom; a casket 

 "containing pearls and jewels worth a thousand pounds"; a buffalo skin; waste material; 

 ropes-ends etc. A swimmer passing within reach of such a voracious creature would plainly 

 run a great risk. 



Some species are thought to be more aggressive than others. The great white shark 

 (Carcharodon carcharias) is also called " man-eater ", a name indicating well enough its sinister 

 reputation. It has been charged with numerous misdeeds. As for the very abundant repre- 

 sentatives of the circumtropical family Carcharinidae, some of these must have a " heavily 

 burdened conscience " on this score. It is true that one lends only to the rich and that public 

 reports have definitely tended to accuse rather than to exonerate the sharks. In this field, 

 our knowledge will certainly benefit in the future from the observations that underwater swim- 

 mers are beginning to make. 



However it must be admitted that man-eating by sharks is only one of the facets of the 

 question. It is rather like a townsman in the fields, who, while crossing a meadow, becomes 

 anxious when faced with a bull and asks himself if the bull will go for him. This anxiety is 

 certainly legitimate, from the view-point of the townsman in question. But it recedes into the 

 background of the concerns of veterinary surgeons and stock-breeders. Similarly that which 

 interests the biologist and fisherman is not so much to know what will be the reaction of a shark 

 in front of a swimmer (so long as they are not themselves in full view, of course...). Their prob- 

 lems lie elsewhere. 



During recent years, sharks have been of vital importance, mainly because their liver-oil 

 is rich in vitamin A. Furthermore, the skin, the fins, the edible flesh and skeleton could be 

 put to profitable uses. And the essential question that faced the fishermen, was to know as 

 precisely as possible what were the species of sharks with the highest quantities of vitamin A 

 in their liver-oils. The psychological reactions of their quarry in no way bothered them. 



For various reasons these industries have recently slackened and then stopped. One 

 day they may be resumed. However this may be, the problems facing biologists and oceano- 

 graphers rest untouched. " These dirty dogs that eat men " are among those oceanic animals 

 whose study offers the most absorbing of interests. 



P. B. 



98 A tropical African cichlid, Hemichromis bimaculatus. 



The paradise-fish, Macropodus opercularis. Photo- 

 graphs by J. M. Baufle. 



