John Alex Ollard, « Pond Life in Midwinter », Londres, Science Gossip, 1883, p. 116-117.
Mr Lake wishes to correct an « erroneous » notion that I have given expression to, and that seemingly on the ground that he has captured caddis worms « in cases which have lost all their greenness ; » but query had they any greenness when first built ? This is omitted. I found, as hundreds I suppose have found before me, that caddis worms build their house according to their surroundings. In a piece of the old New River in White Webbs, where the vegetation was plentiful, the cases were green ; where the surrounding were dark, the cases were dark (decayed leaves, twigs, &c.) ; where shells , shells were used ; and where sand, sans was made up into a little boat with a tube down the middle. I have kept caddis worms, but in no case did their cases turn from their greenness. Will Mr. Lake keep some caddis worms this season with green surroundings, and if he finds their cases lose their greenness, I shall be most happy to acknowledge that my expression are « erroneous, » which maybe they are.