TRICHOP TERA . 1 87 



Family Phryganeim: (Phryg-a-ne'i-dae). 



The Caddice -flies or Caddice -worms. 



The young naturalist loves to lie face downward on the 

 bank of a brook, and, with shaded eyes, watch the busy life 

 that goes on there. Among the astonishing things he sees 

 are little bundles of sticks or masses of stones moving about 

 the bottom of a quiet pool as if they were alive ; and yet if 

 he takes them out they seem dead enough. But when 

 he pulls them apart he finds that each is a tube lined 

 with silk within which a whitish larva lives. This larva, 

 when it wishes to move, puts out the front part of its body, 

 so that it can creep with its legs over the bottom of the 

 stream, or climb up and down water-plants, dragging its 

 house along after it. When molested it draws back into its 

 tube, and is safe. Larvae of this sort are called Caddice- 

 worms ; and the adult insects are known as Caddice-flies. 



There are very many species of Caddice-worms ; and each 

 species makes a particular kind of tube. Some Caddice- 

 worms are carpenters, building their houses of straws or 



sticks. These are usu- 

 ally placed lengthwise 

 the body (Fig. 226); 

 but certain species that 

 FlG - 226 - make their houses chief- 



ly of straws fasten the straws crosswise like the logs of a 

 log-house (Fig. 227). These log-house builders 

 often have the curious habit of decorating their 

 houses by fastening snail-shells to the outside. 

 And strangely enough they do not always take 

 empty shells for this purpose ; we have found 

 shells containing living snails securely fastened FlG 22 'i- 

 to the outside of the house of a Caddice-worm. In this case 

 the snail was afforded comparatively rapid transportation 

 whether it desired it or not. Fortunately the species that 



