SPAWNING HABITS OF CH/ETOPLEURA APICULATA. 253 



2d night, set in two dishes on laboratory tables; one female of 

 medium size spawned maximum quantity (approximately 

 3,000 eggs) ; two others spawned one sixth to one fourth 

 maximum; a fourth laid a few eggs, all before 10 P.M.; 

 an enormous quantity of spermatozoa shed ; white cloudy 

 water. 



3d night, August 20, no eggs ; small amount of spermatozoa. 



Remark. Not many females spawned, but the greatest mass of 

 eggs obtained during this year came from one female of this group. 

 Spermatozoa were particularly abundant. An abundance of 

 spermatozoa has been noted at each full moon, water becoming so 

 turbid that one could not see eggs on the bottom of the shallow dish. 



XIX. 



Experiment ip, August 22-23. 



55 Chitons collected Monday, Aug. 22. 

 ist night, no eggs. 



2d night, only about 50 eggs from a single female ; no visible 

 spermatozoa. 



Remark. Practically no spawning. 



XX. 



Experiment 20, August 24-27. 



60 specimens collected Wednesday, August 24. 



ist night, no eggs. 



2d night, one female spawned two thirds maximum between 

 8-10 P.M.; one male shed spermatozoa; two other fe- 

 males shed eggs before 11.30 P.M., about 300 and 100, 

 respectively ; a fourth female spawned during the night 

 after 11.30 P.M. one half to two thirds maximum. 



3d night, two spawned one third maximum before 10 P.M. 



Remark. Fair spawning activity. 

 * Last Quarter, August 26. 



