110 ITS ADHESION EXPLAINED. 



carnation, with an oval eye-like spot on eacli side, of 

 a deep red hue. 



When put into a vessel of water (no easy matter 

 without injuring it, as it adheres so firmly to its hold), 

 it immediately clings to the side of its new habitation, 

 or to the first solid substance with which it comes into 

 contact. Here it will probably remain for a consider- 

 able time, unmoved, or now and then shift its position 

 a few inches, or take a wayward start, and wriggle 

 along with an awkward sort of agility to some other 

 part of the Aquarium, to which it sticks fast in a 

 moment as before. During the night it is much more 

 restless ; but, so far as I am aware, it has no power of 

 hovering in the water, or swimming deliberately to 

 and fro as other fishes do, its locomotive powers con- 

 sisting only of the ability to shift from one stationary 

 position to another. 



As it thus has no power of pursuing prey, I con- 

 jecture that its subsistence is derived from those 

 microscopic organisms which are scattered abundantly 

 through the water, and which furnish support to mul- 

 titudes of other creatures more strictly immoveable. 

 In the case of these, which are for the most part in- 

 vertebrate, strongly ciliated surfaces are provided, 

 which produce constant and forcible currents, and 

 thus the floating atoms in the surrounding fluid are 

 carried along to the orifice of the digestive canal. 

 Our little Sucking-fish has no external apparatus of 

 cilia, that I am cognisant of, but a similar efl'ect is 

 produced in another way. I have noticed that while 

 this little fish remains stationary, being fast moored 

 by its breast-anchor, it maintains a constant and 



