312 TJic Oaddis-Worm and Us Rouses. 



answers the same purpose to the caddis-worm as the mortar 

 which is used by the bricklayer in the construction of his build- 

 ings. After the foundation has been formed, the caddis pro- 

 ceeds by lifting up with its feet a piece of the material it is 

 employing for its building. This is turned on every side, either 

 in order to discover whether the piece will or will not suit, or 

 else to find out which is the side that will best fit into the space 

 required for it. If the piece is found to answer all the pur- 

 poses required by the caddis, it is cemented into the space 

 reserved for it by this secretion, which as I have stated before, 

 proceeds from its mouth. If, however, the piece does not suit 

 the space, that piece is instantly rejected, and another one is 

 taken up by the worm in the same manner as the previous one 

 was. Sometimes the caddis is obliged to take up several pieces 

 before it is able to meet with one fit for the purpose. This 

 makes the task of building extremely tedious and laborious. 

 Indeed, with the creature's slender legs it seems marvellous 

 that it is able to take up the different pieces with them, par- 

 ticularly when heavy ones are selected, which is the case 

 when the worms inhabit rough waters. For in those localities 

 the materials are principally largo stones, or else thick heavy 

 bits of wood, which must render the building extremely 

 laborious. The building is continued by the caddis in the 

 manner just described without stopping, until it has succeeded 

 in rearing a house according to its taste. When it is com- 

 pletely finished, the whole body of the worm is encased in it, 

 with the cxc('i)1 ion only of its head and legs, and these even are 

 capable of being drawn into its building, either for its pleasuro 

 or for their protection at the appearance of danger. 



Tin; caddises are exceedingly fond of the houses which 

 tlioy lake SO much pains lo build, and it is often very trou- 



biesome to deprive fchem of their habitations. They fasten 

 themselves into the end of their Louses by the means of those 

 two little books which have already been alluded to, and by 

 the aid of which they are enabled to bid defiance to any 

 enemy who might try to denude them of their abodes. 

 When the caddis is once hooked into its case it will often Buffer 



itself to lie torn Into tWO rather than allow it self t o be dragged 

 out. The obstinate noe on the part Of these caddis- 



worm:; often offers some difficulty when it is wished that i\\i-y 

 should build another case. 



but it Will be found that caddises will creep out of their 

 . if slightly irritated by gently pushing a pin into the end 

 of their case. By this method both case and worm will escapo 

 damage and injury. 



Now caddises arc able to make more than one ease for 



ihci \\!i<n former ones are destroyed. When I tried 



