ON" THE BEHAVIOR OF TUBICOL* >l - ANNELIDS. ~l 



large aquarium and left to see whether regeneration would occur 

 and if so at what rate. For a few days it frequently came to the 

 orifice and extended the mantle edge over the margin of the 

 tube and remained in that condition for some time. Later it 

 again withdrew deeply into the tube and did not .-how it-elf for 

 -e\eral da\-, indeed for some three weeks or more. Finally, on 

 l-Vbniary 13 it was once more seen to protrude it- head, but 

 then- was not the least sign of any regeneration It- appearance 

 m>\\ bee, mie more frequent and occasion was taken to test it by 

 -had' >u -, and to my -urpriM- it was found to react as promptly as 

 at tin- \vr\ first. These tests were made main time- on subse- 

 quent da\- with the almost uniformly prompt and po-iii\e re- 

 ai lion, but with the variations observed at first, /'. c.. -ometimc- 

 lc-- -harp, and thru more so, and occasionally not at all. 



Several interesting questions arise- in this connection. I ir-i. 



io i he regenerative capacity of Prptnla. For lu.uK tun 



month- mil a sign of regeneration was distinguishable. 1 had 



pie\iou-ly recorded ('06) tin- promptness with \\hieh Ilydronlcs 



:ated ii- gill-, and similar records had also been made 1>\ 



/elen\ . I inalK on March 14 1 found undoubted e\ ideiice ol 



n< raiion. and thi- went forward apparently rather rapidlx . 



ti.i b\ April 10 the new gills had become quite om-picimu- 



nearK a tilth as large as the originals, h mav be noted here 



that Liter I had also a similar autotomy by another -pecimeii 



ot /'"'//i/i/ and by two sjK'cinu'ns of Spirogra (this. In tin-' 



there tdiild not be doubt as to any condition of water inducing 



the auiimy, for the specimens continued to thri\e. as did 



man\ otln-r- in the sanu- lank. Re-generation u.i- very pn>m]>t 



and rapid in these cases. 



\ -e.-i.nd |toint is in relation to such c.ne|.iti..n of funcii.m 

 .1- ui.uld enable tin- creature during lhi> IOIIL; ]>eri'd (' gill 

 depri\aii'>n to maintain the normal rc--piratm \ activity. It 

 n--|iilalii>n \\ere restricted to the gill- almie nf course it nui-t 

 ha\e i>eri-ln'd. This experiment sho\\ - learU that thi- func- 

 tion may be taken up by other organ- of the body without 

 serious inci>n\enieiuv. But the gills are also concerned in the 

 process i nutrition, acting as a medium for capture of prey. 

 How might this function have beeen Mippleim-nu-d.-' It has 



