434 BENJAMIN H. GRAVE. 



* September 7, first quarter. 



XXIII. 9/9. 6 females spawned, i 2/3 maximum, 4 1/5 maximum, i i/io 



maximum. 5 males shed sperm, 31/2 maximum, 2 light. 19 did not 

 spawn. 



Comment. Considerable revival of spawning noted. Much more active than 

 last week, but still relatively insignificant. Good for so late in the season. 



* September 21, full moon. 



XXIV. 9/21. 3 females spawned, i maximum, i 1/5 maximum, i i/io maximum. 



2 males shed sperm, i 3/4 maximum, i 1/2 maximum. 15 did not 

 spawn. 



Comment. Revival of spawning evident, though not extensive. Quantities 

 surprisingly large. Temperature 18 C., or 173 C. 



XXV. 9/10. Temperature 17 C. No eggs and no sperm. 



Comment. The spawning season of Cumingia ends between September 15 and 

 October i. This year spawning continued until the end of September. The 

 foregoing data give no very definite information about the time of spawning in 

 nature. It is evident that eggs are produced almost continuously although probably 

 not uniformly. There is a lunar periodicity either in the production of the gametes 

 or in the spawning or in both. Spawning by each individual occurs more than 

 once during the season. 



BIBLIOGRAPHY. 



Mr. H. Munroe Fox gives a fairly complete bibliography of papers that dea 

 with lunar periodicity in his paper entitled "Lunar Periodicity in Reproduction. 1 ' 

 Proc. Royal Soc., Vol. 95 (1923). It seems unnecessary to include them all here. 

 I select a few that are likely to be of local interest or important to the general 

 reader. 



1. Crozier, W. J. 



'22 An Observation of Cluster Formation of the Sperms of Chiton. Am. Nat., 

 Vol. 56, p. 478. 



2. Friedlander, B. 



'98-'o4 Ueber den sogennanten Palolowurm. Biol. Centralbl., Vols. 18, 19, 21, 

 and 27. 



3. Fox H. Munroe. 



*22-'23 Lunar Periodicity in Reproduction. Nature, Vol. 109 (1922) and 

 Proceedings of the Royal Soc. B, Vol. 95, p. 523 (1923). 



4. Grave, B. H. 



'22 An Analysis of the Spawning Habits and Spawning Stimuli of Ch&topleura 

 apiculata. BIOL. BULL., Vol. 42. 



5. Hempelmann, F. 



'n Zur Naturgeschichte von Nereis dumerilii. Zoologica, Vol. 25. 



6. Hoyt, W. D. 



'07 Periodicity in the Production of the Sexual Cells of Dictyota dichotomi. 

 Bot. Gaz., Vol. 43. 



7. Just, E. E. 



'14 Breeding Habits of the Heteronereis form of Platynereis megalops at Woods 

 Hole, Mass. BIOL. BULL., Vol. 27. 



8. Just, E. E. 



'20 The Fertilization Reaction in Rchinarachnis parma. BIOL. BULL., Vol. 30. 



