ON THE BEHAVIOR OF TUHICOl.orS ANNELIDS. 



75 



ol>MT\ation brings to li^lit too many exception^ to any such 

 rule, and compels further inquiry. Like other species of 7/v- 

 <lroide.s this one secretes a calcareous tube, the shape of which 

 <1 -pi -nd- upon the mode of growth of tin- individual constructing 

 it. Hence in aspect, size, etc., these become permanent records 

 ol rvrryduy behavior, whether thi- be mf.-hanic.il, ecological, <,r 

 physiological in its nature. Several coloim- \\i-re put under 



-Ih'ws three colonies of H\dri,: :.it<i whirh 1. 



lixlit U'-t i. n in. nr than a month. As will be seen the curvings of the tubes 



iinii h u- in \ \ + . I . 



i \ .iiion c,irl\- in January arid urn- u--trd during a period of 

 mu<- than tluve months; to be more exact, lunn |.iim,ir\ .^ lo 

 April i:r. 'l"he\- were tested as to the po-^ibK- inlliu-nce of both 

 li.uht and i;ra\it\-. Loeb claims that in thi- -pccif- tlu- reaction 

 i- .|iiitr prompi. ' I noticrd that in tin- course of the nc\i day 



