36 THE BROOK BOOK 



attaching it securely, to carry shell and owner 

 wherever they go, without so much as saying "by 

 your leave." Among the most curious of these is 

 the species which constructs cases of sand in close 

 imitation of snail shells. These are often attached 

 in colonies to stones in streams. Why they should 

 thus infringe on the snail's patent is a mystery. 



The houses of the nomadic caddice-worms are 

 well ventilated, which is more than may be said of 

 their human namesakes. A front doorway and a 

 back doorway, with no doors to open and shut, — 

 a thoroughly simple and entirely effective system. 

 Sometimes there will be a screen of silk over the 

 small back doorway, but it is usually wide open 

 while the owner is active. The healthy caddice- 

 worm simply revels in a constant stream of cold 

 water; a draught never gives him a cold. 



The builder of the caddice case, whether it be 

 of stone, wood or sand, is also a spinner of a sort 

 of silk fiber useful ofttimes in holding the building 

 materials together and in making the inside of the 

 house comfortable. The caddice-worms are fond 

 of silk linings. Since they have no furniture they 

 upholster the whole house inside, sparing no pains 

 to make it smooth and soft and suitable for their 

 uses. If deprived of its case the caddice-worm 

 makes a new one. It will even do this in the 

 aquarium for some people — but not for me. 



