INSECT ARCHITECTURE 107 



creatures are not at all particular about the 

 straightness of the sticks, but take them of any 

 degrees of curvature. . . . Another case is made 

 of the hollow stems of some plant, apparently 

 that of a hemlock, to which are attached a few 

 slips of bark from the plants. Next comes a 

 series of cases in which the caddis larva has 

 contrived to secure a great number of cylindrical 

 grass-stems, and arranged them transversely into 

 several sets, making one set cross the other so as 

 to leave a central space in which the little archi- 

 tect can live. 



' One or two cases are made wholly of bark, 

 apparently the cuticle of the common reed, a 

 plant which is very common in the Cherwell, 

 whence the cases were taken. In all probability 

 these strips of cuticle have been dropped into the 

 river by the water-rats while feeding on the 

 reeds. 



* Several cases are made entirely of leaves, 

 mostly taken from the whitethorn, which grows 

 in great quantities along the banks of the above- 

 mentioned river. Then there are cases which 

 are entirely composed of sticks and leaves, these 

 materials generally occupying opposite ends of 

 the case. There is another series of cases made 

 up of fine grass, apparently the debris of hay 

 which has been blown into the water during the 

 summer, and having the materials laid across each 



