in Confinement. 3635 



shell, move some little distance, in a horizontal direction, from the 

 point which they had left. On more carefully watching this pheno- 

 menon, however, I found they were attached by a thread or web, which 

 was so transparent as to be altogether invisible, and which they could 

 elongate in a similar way to the spider ; they also possessed the power 

 of returning upon this thread by gathering it up as it were, and thus 

 drawing themselves back to the point which they had quitted. These 

 facts were clearly proved in the following manner : — A Limnea stag- 

 nalis had glided its way along a young and short leaf of the Vallisne- 

 ria which terminated below the surface of the water, and having reached 

 the extremity launched itself off from it ; after moving about with a 

 sort of swimming or rolling motion in a horizontal direction for some 

 time it lowered itself gradually, and in effecting this the long flexible 

 leaf of the Vallisneria was bent with an undulating motion, corre- 

 sponding exactly with every movement of the snail, clearly showing 

 that it had a firm attachment to the extremity of the leaf. On another 

 occasion a Limnea glutinosa gradually rose from the surface of a piece 

 of submersed rock, and when at the distance of about 3 or 4 inches 

 from it stayed its progress, floating about in a circumscribed horizon- 

 tal direction for some time ; at last it rose suddenly and rapidly to the 

 surface, evidently from the rupture of its thread of attachment. The 

 most convincing proof, however, of this fact that I can perhaps ad- 

 duce, and one that I have often repeated with all the before-mentioned 

 Limneae, is that when the snail has been some inches distant from the 

 supposed point of attachment, a rod or stick has been carefully intro- 

 duced, and slowly drawn on one side between them in a horizontal 

 direction, and by this means the snail can be made to undulate to and 

 fro, obeying exactly the movement of the rod : this requires to be done 

 very gently, as, if too much force is used, the web is broken, and the 

 snail rises rapidly to the surface. 



The next subject of interest which I wish to call attention to is — 

 The Stickleback, {Gasterosteus leiurus). This most beautiful little 

 creature has afforded a subject for much interesting observation for 

 some time past, and I fear that what 1 have to offer will prove very 

 much a repetition of what has already been published on the subject. 

 As, however, the proceedings and observations of those who dare not 

 rank themselves in the class of naturalists, sometimes from their want 

 of knowledge, cause circumstances to arise which would not otherwise 

 occur, so in the present case my failures through my own ignorance 

 may develope some new points in the (Economy of these small fry. 

 Mr. Edwards, of Shoreditch, whose London garden pond has afforded 



