THE BRICK-MAKER. 25 



thought it retires within its stronghold. But if 

 now we wait and watch we shall perceive two 

 fine projecting points, tipped with fine setae or 

 hristles : these are feelers or antennae, and give 

 the required information as to danger. When 

 satisfied as to its security, it prepares to come 

 out and resume work : there is a gentle trembling 

 and quivering around the bulwarks ; the head is 

 thrust out and again withdrawn, as if in doubt 

 of safety. Finally assured, the flower-like trochal 

 disc is gently expanded and unfolded. 



There is another Melicertan which merits 

 mention, although it has been named " Tyro," by 

 comparison with its more exalted neighbour. The 

 reason of this designation being that while the 

 creature is furnished with the ciliated cup, i.e., 

 pug-mill or brick-making machine, it yet does not 

 make any bricks at all. The organisation and 

 material are both supplied, yet no result appears. 

 This is not the usual method of nature's working 

 in the ascending or progressive scale of development, 

 and the disuse of this organ must be rather regarded 

 either as indicating reversion or retrogression, than 

 an attempt to reach the level of M. ringens, which 



