BDELLO STOMA DOM BEY I, LAC. 133 



disturb Elasmobranchs. They devour their own eggs, and I 



have frequently taken the remains of small squids from the 



stomachs of these animals. It is certain that they do penetrate 



the bodies of such iish as the Halibut, the Flounder, the Rock 



Cod and Codfish, though there is not the slightest evidence 



that they do so while the fish is in the living condition. They 



might readily do so, however, and the fishermen all believe that 



they do attack living fishes and bore their way into them. This 



much is certain ; very frequently fish are taken in the trawl 



nets from which one may see the Bdellostoma issuing in haste 



to o:et into the water again. These fish hulks are found to be, 



usually, thoroughly despoiled of all their soft parts. They 



retain the fish form by means of the skeleton within an intact 



sl^in — intact with the exception of the small hole in the region 



of the "'ills throuu'h which the squirming fish was seen to come. 



Since Bdellostoma bites the sardine-baited, trawl-line hooks of 



the fishermen with extreme avidity,^ and is able to swallow 



pieces of fish or other food nearly as large as its own ordinary 



diameter, it does not seem to be entirely correct to designate it 



a strictly parasitic animal. And if it is not parasitic, its sense 



organs can hardly be said to have been degraded by parasitism. 



If they are not degraded, they must represent primitive 



conditions, and so far as the structure of the nose, eye and 



ear are known to us, they contain absolutely no anatomical 



characters which would justify the conclusion that they are 



degraded from a more perfect ancestral condition. The eye 



lies beneath the skin, it is true, but this is doubtless a stage in 



the phylogenetic development of the eye, just as the existing 



and very primitive condition of the nose is, without question, 



a stage in the genesis of the nose of higher forms. 



The head end of Bdellostoma is obliquely cut off from above, 

 downwards and backwards, in such a fashion as to bring the 

 anterior end of the long tubular nose at the extreme front 

 end of the body ; and since this anterior nasal aperture is 



1 The trawl-lines are often brought up with as many Bdellostomas as other fishes, 

 and my Chinaman assured me that sometimes nearly all of the hooks were taken 

 by this Ilagfish; or, as he expressed it, " Evely hook — one Sliklostome," i.e. 

 Cyclostome — he having learned the scientific name of the creature from the 

 students of the Hopkins Laboratory. 



