SPAWN OF THE SUCKER. 119 



an obvious reason why the head should be affixed to 

 the surface during the dislodgement of the adhering 

 prey,, in order to acquire greater steadiness, as well as 

 a leverage by which to act more effectively. What 

 confirms this view, is, that though the fish may con- 

 tinue to be seen, say on the ship's rudder, for hours, 

 it is not continually adhering ; but ever and anon 

 shifts its position, detaching itself for a moment, and 

 then adhering again instantly. 



Several times lately I have had brought up in the 

 dredge, old valves of the Cookie, Scallop and Oyster, 

 the concave surfaces of which were partly covered 

 with considerable patches of what looked like amber- 

 coloured beads, — such as are used to make bead- 

 purses, — set as close as they could lie, but only in a 

 single layer. They adhere quite firmly to the shell ; 

 and I knew that they were the spawn of some fish or 

 crustacean, but was at a loss to know what. On one 

 occasion, in the middle of the summer, I found the 

 little fry escaping, so that the glass vase into which I 

 had dropped the valve, was presently quite peopled 

 with tiny fry ; their gelatinous hyaline bodies barely 

 visible, and their presence only indicated by the pair 

 of lustrous, green goggle-eyes, which with the inter- 

 vening head constituted by far the greatest portion of 

 each little creature. 



From that charming work " Excursions to Arran," 

 by the Bev. D. Landsborough, jD.D., I learn that 

 this spawn was laid by the little Two-spotted Sucker. 



DOUBLE VISION. 



There is a phenomenon which has long been noticed 



