Sucking-fish Parasites 251 



naturalist in the study of the deep-sea fauna. He is 

 so greatly dependent upon stray specimens brought 

 home for his observation, he cannot, in the nature 

 of things, bring personal experience to bear, and he 

 must theorise largely. Which of course tends to error, 

 since it is, to a great extent, working in the dark. 

 I have had a curious instance of this while preparing 

 the present chapter. 



In previous pages I have described the Remora, 

 or parasitical sucking-fish, under the head of sharks, 

 because every specimen I have seen, and they run 

 into hundreds, have possessed aU the well-known 

 characteristics of the shark. The curious leaden 

 and white hue of the body, the long upper lobe of the 

 tail fin, the strange eye full of sinister expression, 

 the scaleless shagreen skin, making a very good sub- 

 stitute for sandpaper, and the gill-openings, just slits 

 in the side of the neck, instead of one large free opening 

 spreading wide and admitting the water to the blood- 

 red feathery branchiae inside ; all these marked my 

 suckers and stamped them as sharks. Only there 

 was superadded the curious oval sucker on top of the 

 head, by means of which the lazy creature attaches 

 itself to its host, whether it be living or dead. Now 

 I am told that the Remora is not a shark at all, but 

 a mackerel. Of course, I can fully understand that 

 there may very well be a species of Remora which is 

 a mackerel, but that I have only seen the kind which 

 has the shark characteristics I have absolutely no 

 doubt whatever. 



I cannot understand why so familiar a fish as it 

 is, being certainly much more frequently seen at sea 

 than the species which I do not know, should be un- 

 known to the authorities. There is, therefore, all the 

 more credit due to them for having rejected all the 



