36 



always so very regular in the ti-;e for leoositing their egJTS , 

 v/hich is from fivo to six A. ;:. During the two sujixers that 

 I studied Turritoosis at the sea-shore, great nurrbers were 

 collected and ke'it in acuaria. On T-any occasions larose 

 early in the "orning to observe the act of spawning,- one 

 ti"ie they were watched through the en .ire night,- and always 

 the act of egg layincr was seen to oomnence at about five 

 o'cloc:: or a few minutes after. Very rarely did it take 

 olace as late as six o'clock; and on no occasion was the nhe- 

 noTenon observed more than a few minutes before 5 A, ivl. 



Ihis Drecise periodicity is rot O'-l-j i confined to Tur- 

 ritorsis, but seeTs to be cuit^e prevalent arong the cedusae 

 in general. In Stcrr.otoca a icata. Stonotoca rugpsa and a 

 species of Ei|cheilpta I find that the eggs are deposited 

 also at a fixed hour, nar^ely, 5 to 5.30 A. I'. Professor 

 Broo::s found that Lirope and Eutina sr>awn at about S P. .M. 

 In Gon ionema Perkins found the time to be fron 7 to G P. i.'.. 

 Bunting found the neriod of dehiscence for Hyd ractinia to be 

 about 10 P. :... While ;..ere.ikowsky says that the eggs of 



