SPAWNING HABITS OF CH^TOPLEURA APICULATA. 249 



2d night, experiment set as usual 6 P.M.; those in quiet 

 water began to shed spermatozoa about 7.30 P.M. 

 (one male) ; between 7-10 P.M. three females 

 spawned in quantity two thirds maximum in one 

 dish; three others spawned in quantity in another 

 dish (about 30 chitons per dish) ; no eggs obtained 

 from dish in running water. 



3d night, no eggs obtained ; experiment not set until TO 

 P.M. 



Remark. Spawning distinctly revived. For ten days preceding 

 no eggs obtainable for class work. Was unable to get eggs for 

 embryology class during first half of July. Spawning revived 

 three days before full moon. 



VIII. 



Experiment 8, July 16-19. 



ist night, about 50 chitons placed in crystallizing dish on laboratory 

 table at 10 P.M. (too late). (Collected during afternoon of 

 July 1 6.) No eggs first night. 



2d night, five specimens spawned rather lightly one fourth maxi- 

 mum ; one mass of considerable size, three fourths maximum 

 or more ; eggs in addition scattered all over the bottom of the 

 dish. 



3d night, two or three females spawned lightly before 10 P.M.; 

 very few eggs ; one fair-sized group. 



4th night, no eggs. 



Remark. Spawning by this group was not particularly heavy. 

 More eggs were spawned by previous group July 15. Not a great 

 difference and not inconsiderable. 



* Full moon, July 19. 



IX. 



Experiment 9, July 20-22. 



40 specimens collected July 20. Placed on laboratory table at 

 6 P.M. Three females spawned lightly before 10 P.M. 

 About 50 eggs each. None after 10 P.M. 



