ON THE CAUSE OF AITOTOMY IX TTBULARIA. 



OSCAR RIDDLE. 



In the cour-e of studies on the oxidizing and reducing; poxxer- 

 of ilir xariou- ti--ue- and body re-ion- of h\ dromedu-a 1 the 

 phenomenon of .uUotoniy \\a- ob-erx ed to occur so -enerallx- 

 and SO rapidly in Tidndar'm as to invite attention to it- cause. 

 That Tnhulariti \- capable of aiiioiomy /. e., of the -elf-dix i-ion 

 of it- bodx ha- Ion- been known, the process haxin- been ob- 

 -erxed b\ (liard. Loeb, Drie-ch. Morgan, and other-. Two in- 

 vestigators ha\e definitely -on-lu in determine thi of the 

 phenomenon. The conrln-ion- \ the-e two worker- seem, ho\\ - 

 i-\er. not to be in accord. < "lodleu.-ki 1 maintain- that degenera- 

 tion of i he h\ dram 1 1 precedes and condition-, the autotomy, so 



that il i- a <l>>. lie rdtcd ludranth that i- -e\etvd from the body. 



Mo -\\ho seems unfortunately to ha\e o\erlooked ('.odiew- 

 -ki'- pajier \\ritin.u in this journal -tate- that antotoiny ma\ r 

 Mr \\itlioui an initi.il de-eiu-r.it ion in the ludranth, if one 

 i an ind-e of ihi- liom hi-iolo-i( al examination. 



M \ o\\ n experience with autotomizing 'I't-.-ndnria indicate- thai 



\\lu-ii thi- ]n is effected \er\ -lo\\l\ and -^radnalK', .1- i- 



orilinarilx the ne can c.rlainK -ometinu- lind. as did 



< ,oillc\\ ^ki, that before the actual -e|iaration of ihe lixdranth 



the latter ha- undergone -iderable degeneration. ( h\ the 



other hand. I ha\e had main aiitoi. >mi/ed Indranth- to !i\e in 

 a|>]i.irentl\ p-rfect condition for three and lour day >. < .odle\\ -ki 

 hiin-el! noie- one Mich hydranth \\hich li\ed lor t\\o day-,. It 

 i- quite easy, tOO, to confirm Mor-e's -tatement that a ri-c- in 

 temperatiiu- tax or-, the occurrence of autotomy. Neverthel< 

 the peculiar conditions under which I \\a- able to obserx e the 

 aiitotomx conxinced nu- that neither of the aboxe mentioned 

 Mil)po-ed causes, nor xet both combined, i- the immediate or 



' .i!li-\v-ki. 1" . "/in Ki-niUin- del K'-v;iiLitii'r. i I :i>> iiltiriii 



:ul." l\.-:i\' ArchtV, \'-l. I S, I')04. 



'Morse, M the II>ai.nuh -i 'I'u'-ulnria." 



Hei i i i IN. \',.l. if.. 1909. 



389 



