250 B. H. GRAVE. 



2cl night, placed on laboratory table at 7 P.M.; three or 

 four spawned one third to one half maximum or 

 more before 10.30 P.M., mostly before 9 P.M.; 

 spermatozoa abundant; none after n P.M. 



3d night, four females spawned about twenty eggs each ; 

 practically none at all. 



Remark. Only fair spawning activity. Plenty of eggs for 

 class, however, and approximately equal to the two preceding ex- 

 periments, 7 and 8. Spermatozoa were abundant. 



Experiment 10, July 25-26. 



70 specimens collected Monday, July 25. Mostly half or two 

 thirds grown, but sexually mature. 



ist night, five spawned, one half to two thirds maximum. 

 2d night, six or seven spawned ; four of them one half to 

 two thirds maximum ; impression of fair or good 

 spawning activity ; good quantity as spawning goes 

 this year ; perhaps as heavy as the best this season ; 

 comparable to that of the last week in June, but prob- 

 ably not quite equal to it. 

 * Last Quarter, July 27. 



XL 



Experiment n, July 27-29. 



75 Chitons collected Wednesday, July 27. Placed in two dishes 

 upon laboratory table. None spawned ist night, except a very 

 few eggs from two or three individuals. Negligible. 



2d night, six specimens spawned about one third to one 

 half maximum; all spawned before 10 P.M.; mostly 

 between 8-10 P.M. (There were only 45 specimens 

 used this 2d night. Several had been lost.) 

 3d night, no eggs. 



i 



Remark. Good spawning activity. 



