BREEDING HABITS OF HETERONEREIS. 1 59 



Some other annelids (e. g., Amphitrite; see Scott, 1909) exhibit 

 a lunar periodicity in breeding habits. The periodicity in Nereis 

 limhata thus belongs to a large class of phenomena, which includes 

 breeding seasons of some plants as well as many other animals, 

 for which no adequate general cause has yet been found. 



III. The Life History of Nereis limbata. 



This subject is still under investigation. It is obvious that 

 interpretation of the swarming behavior must wait for fairly 

 complete knowledge of the life history. The present indications 

 are that the worms either do not mature in the atokous condition, 

 or, if they do so, that it is at an earlier time of year than our collec- 

 tions were made. The atokous forms were secured both in 

 scrapings from piles of wharves and also by digging, and were 

 kept under observation in the laboratory. All that matured 

 ""underwent metamorphosis to the epitokous condition. Despite 

 repeated eflforts we failed to rear mature worms from artificially 

 fertilized eggs. However, a few were raised to 3'oung worms 

 about 5 mm. in length, about eight weeks after fertilization; but 

 all of them died after an attempted change in culture methods. 



LITERATURE REFERRED TO. 

 Friedlander, Benedict. 



'98 Ueber den sogenannten Palolovvurm. Biol. C'bl., Vol. XVIII. 

 Galloway, T. "W., and Welch, Paul S. 



'11 Studies on a Phosphorescent Bermudan Annelid, Odonlosyllis enopla 

 \'errill. Trans. Am. Entomological Soc, Vol. XXX. 

 Hempelmann, Fr. 



'11 Zur Naturgeschichte von Nereis Dumerilii Aud. et Edw. Zoologica, Bd. 

 25, Lief. I (Heft 62). 

 Izuka, Akira. 



'03 Observations on the Japanese Palolo. Journ. Coll. Imp. Univ., Tokyo, 

 Vol. XVII., Art. II. 

 Mayer, A. G. 



'02 The Atlantic Palolo. Science Bulletin, Mas. Brooklyn Acad. Arts and 



Sci., Vol I. 

 '03 An Atlantic Palolo, Slaurocephalus gregarious. 

 '07 The Annual Swarming of the Atlantic Palolo. Seventh Internal. Zool. 



Congress. 

 '08 Publication 102 Carnegie Inst., Washington. 

 Scott, John W. 



'09 Some Egg-laying Habits of A w/»/ji/rt<eorrea/aVerrill. Biol. Bull., Vol. XVII. 



