Sticklebacks at Home. 139 



did what she no doubt thought best fitted to my 

 understanding, and what could not be unsuccessful 

 even with a blind man she led me to the place; and 

 sure enough there was the pond, a flat hole, filled up 

 at one side with a dunghill, bounded on another by 

 rubbish, and strewed over with fragments of buckets 

 and earthenware rejected from the manure, the 

 unsubsided mud floating up to within a few inches of 

 the top. Still, amidst all these impurities, the stickle- 

 backs were there in shoals, gay, fat, and healthy. I 

 took of them with a small net what I required, and 

 returned home, rejoicing at my good fortune." 



The previous year he had been making experiments 

 with the common mussel experiments the descrip- 

 tion of which is well worth reproducing both on its 

 own account and as showing how fertile in interest the 

 commonest objects may become to a question-asking 

 mind : 



" I have been much interested," he says, " in 

 watching the habits of a common mussel (Mytilus 

 edulis), which has afforded me many hours of pleasant 

 amusement. It had been in my keeping for three 

 months. I had taken little notice of it, till, finding 

 that it had removed from the bottom, and attached 

 itself about two inches up the side of the jar, I became 

 curious to know how it had got up. I observed that 

 the fibres of the byssus were fixed at various heights, 

 that the lowermost were fully an inch from the 

 bottom ; that by their apparent contraction it could 

 raise itself nearly an inch ; and that from this position 

 other fibres could be and had been fixed higher up ; 

 hence the ascent. It remained in this position for 



