Edward Step, Marvel of Insect Life, Londres, Hutchinson, circa 1920. p. 450.
Then they set to work constructing a small case of any suitable material they find handy. They are born with the knowledge that protection from the numerous enemies the water contains is an essential of existence. Pretty little objects they are at this stahe, as they roam over the weeds and the bottom. Spinning a tube of paper-like silk around the body, they attach foreign substances to it as they proceed. As they grow bigger the case requires to be enlarged to accomodate them, and this is effected in a very ingenious manner. All additions are made to the front end. The fore-body, to which the legs are attached, being the broadest part, additions to the case suficient to surround this part will provide ample accomodation for the hind-body later. But such additions would soon make the case of unnecessary length ; so the grub cuts off a portion at the rear each time it adds to the front, and keeps the same house for its use until it acquires wings, though before that time the case has been gradually remade entirely.