294 D - D - WHITNEY. 



Lot A. April 25. Put three of the white hydras into a large 

 balanced aquarium. Food added every 24 hours. 



April 27. The three hydras were larger and each had one bud 

 attached. 



April 28. The buds had become detached from parent hydras. 



April 30. The buds were larger than when detached. Each 

 of the 3 parent individuals was budding again. 



May 1. One of the parent hydras had two buds attached. 



May 2. Nine individuals. Two of the parent hydras were 

 budding. None showed a trace of green color under the lens. 



May 5. Eleven individuals. 



May 8. Twelve individuals, 5 of which were budding. 



May 10. Sixteen individuals, 4 of which were budding, one 

 had 2 buds. None showed a trace of green color under the lens. 



May 27. Many white hydras on lighted side of aquarium. 



Lot B. April 27. Put 6 white hydras into another large 

 balanced aquarium which contained green hydras. The white 

 hydras were not in very good condition ; they were fed daily with 

 rotifers. 



May I. Only two white hydras alive. 



May 13. Several white hydras seen on walls of aquarium in 

 the midst of the green ones. Some individuals were budding. 



May 27. Many white hydras on the lighted side of aquarium. 



Experiment XII. — April 4. Put one Hydra fusca together with 

 many Hydra viridis into a .5 per cent, solution of glycerine with- 

 out food. 



April 14. Food added. 



May 1. Twelve of the Hydra viridis had lost all green color. 



Hydra fusca was reddish orange in color. It had produced 

 several buds. 



May 8. Eight Hydra fusca, three of which were budded. Much 

 larger and very different in color from the Hydra viridis that 

 had lost their green color. 



May 13. Thirteen Hydra fusca. Two individuals had 1 bud, 

 3 had 2 buds and 2 had 3 buds attached. 



Experiment XIII. — April 14. Put several green hydras into 

 a .5 per cent, glycerine solution. Food added daily. 



May 10. Some hydras had no visible green color and were 

 rather small in size. 



