SHARKS 29 



sharks," writes Dr. Gudger, " that they may rather easily be 

 driven into shallow water and caught without harpooning. 

 . . . My men used to drive them into shallow water, catch 

 and drag them up on the beach, and after 1 had finished 

 measuring and examining them, put them back into the water." 



In their breeding the Nurse Sharks are ovo-viviparous ; that 

 it to say, the eggs are shed from the ovaries, passed into a 

 shell-gland where they are enveloped in a brownish-black 

 horny case, and then lie in the lower part of the oviduct (the 

 passage leading from the ovary to the exterior) until the young 

 are finally hatched by the breaking of the shell. It is probable 

 that the ancestors of these sharks produced eggs, which were 

 deposited in cases in the open sea like those of the Dogfishes, 

 and that to-day they are on the way to becoming viviparous, 

 but still retain the egg-capsule within the body of the mother. 



The skin of the Nurse Sharks, with its very small, close- 

 set, tile-like denticles, is said to provide a particularly good 

 shagreen. They seem to have little other economic value. 



The name " nurse " would seem to be a contemptuous 

 epithet, and to refer to the ease with which they may be cap- 

 tured. "Nurse" or "Nusse" is also an ancient term for a 

 large fish. As early as 1699 we find in Dampier's ' First 

 Voyage to Campeachy a reference to " sharks, sword-fishes, 

 and nurses ". Dampier states that " the Nurse is just like a 

 Shark, only its skin is rougher, and is used for making the 

 finest Rasps ". The scientific name, Ginglymostoma, is derived 

 from two Greek words meaning " hinge " and " mouth ". 



WHALE SHARK. 



(Genus Rhineodon.) PL II a. 



A very large Shark, with a long, nearly cylindrical body, 

 and a broad, blunt head. The upper part of the body is 

 provided with curious keels or ridges, running lengthwise, one 

 along the middle line of the back and 2 or 3 on each side. The 

 eyes are small and without folds below. The large straight 

 mouth is nearly at the end of the head, and each of the jaws is 

 armed with a band of numerous, very small, curved teeth, 

 forming a kind of rasp. The spiracles are small and are placed 



