328 TOILERS IN THE SEA. 



The animals testify a decided preference on choosing 

 the materials of their habitations. While always 

 preferring sand, and comminuted shell, pounded glass 

 is sparingly and reluctantly employed, and unless 

 for a few fragments, it is soon entirely rejected. But 

 there is a striking difference in the character of the 

 tubes. One is short and confined, extending little 

 beyond mere accommodation for the body ; another 

 is considerably prolonged, so as to afford a safe retreat 

 in times of danger. The architect of a third seems 

 to persist in advancing the fabric, as long as it can 

 procure materials. It never wearies of working. 

 Night is the chief season of architectural labour, 

 though perfect idleness never leaves the day unoccu- 

 pied. By means of the tentacular organs, and the 

 cleft in the anterior part, grains of sand are selected 

 and adapted to the precise spot, where glutinous 

 matter secures them to the tube for sheltering its 

 otherwise defenseless tenant." 



The tubes of the scarcely common English species 

 (Sabcllaria anglicd] form irregular masses, generally 

 fixed amongst the branching roots of the large sea- 

 weeds (Laminaria) or heaped on old shells and 

 stones. The size has no definite limits, and some- 

 times the tubes are solitary. In most cases the 

 tubes are irregularly mixed, flexuous, an inch to 

 .an inch and a half in length, the spaces between 

 .them filled with sand, of the same kind as that of 



