244 APPENDIX. 



INGENIOUS EXPEEIMENT WITH THE FRESH-WATER 



CADDIS. 



Page 50. 



"& 



" My efforts to promote the practical application 

 of observed facts of natural history during the 

 deHvery of my lecture on ' Fish Hatching/ at the 

 E-oyal Institution, have been so handsomely and 

 flatteringly mentioned in your columns, that I 

 cannot refrain from giving more details about one 

 of the sj)ecimens I placed upon the table to illus- 

 trate my subject, and this because it was the handi- 

 work of a lady, or, rather, it was the idea of a lady 

 carried out by representatives of a humble class of 

 insects. 



"Everybody knows the humble caddis worm, 

 that neglected but really interesting creature which 

 is found so plentifully in ponds and stagnant ditches. 

 If you will examine one of them you will find that 

 the creature has surrounded his body and built for 

 himself a movable house — like the gipsy's moving 

 caravan — of sticks, stones, water- shells — in fact, 

 any material he could get hold of; just as we our- 

 selves at Brighton build houses and walls of flints, 

 or in London dig up the London clay (as it is 

 called b}^ geologists), and, having baked it into 

 bricks, build our houses of the materials nearest at 

 hand. If we want further illustrations, look, 

 reader, at the substance with which your own house 

 is built. If you are at Bath, you mil find it is 

 built of Bath stone ; if at Oxford, of oolite ; if in 

 Cornwall, of granite, and so on. Just in the same 

 way the caddis, living in a ditch, builds his house 



