APPENDIX. 245 



of the materials of which the bottom of the ditch 

 is formed. 



"Now, an ingenious-minded, observant, and 

 clever-fingered young lady. Miss Smee — daughter 

 of Alfred Smee, Esq., whose practical and clever 

 researches in science are so well known — reasoned 

 that if the caddis were taken out of the house 

 which he had formed from the materials he found 

 at the bottom of the Wandle, and given materials 

 wherewith to build a new house, he would rather 

 use these, whatever they might happen to be, than 

 have no house at aU. She therefore set to work, 

 and put the caddis to work also; for, having 

 despoiled him of his house, she gave him other 

 materials which he might use or leave alone as 

 he chose. The consequence of her most interest- 

 ing experiments was that she has been enabled 

 to show a glass case, neatly fitted up, containing 

 specimens of the most curious caddis-houses that 

 have ever been seen by the naturalist. In this 

 collection we find caddis-houses made of the fol- 

 lowing most nn-caddis-Hke materials, viz., bits of 

 glass, both white and coloured, of coral, of ame- 

 thyst, onyx, cairngorm, gold, silver, brass, and 

 numerous other materials which the ingenuity of 

 Miss Smee had devised, forming altogether a re- 

 markable example of how human intelligence can 

 cause the instinct of minor creatures to work for 

 man, according to its own design. The caddis 

 refused to use bits of coal, brick, or slate ; also tin, 

 lead, or copper. Miss Smee observed that the 

 greatest number of houses that a caddis would 

 build was five, and that every house they formed 

 was more and more fragile. They cement the bits 



