68 



Papers from the Marine Biological Laboratory at Torlugas. 



laboratory, at temperatures ranging from 27.1° to 30.1° C, from June 19 

 to July II, 191 1, at Tortugas, Florida. The medusae were kept in a 6-liter 

 glass aquarium, the water being changed once in each 24 hours. 



Table 7. 



1 According to formula y = 497(1 — 0.0529)^. 



Remarks. — Free-swimming algal cells were given off from these medusae everj' morning soon after day- 

 light for the first week. These plant-cells collected on the side of the cylindrical glass aquarium which was 

 away from the light. 



U medusae of Cassiopea starved 

 22 days in diffuse day-light 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 



Days X 

 Diagram illustrating Table 7. 



Table 8 shows the decline in weight of a single normal medusa of Cassi- 

 opea xamachana starved 17 days in the diffuse daylight of the laboratory in 

 filtered sea-water at temperatures ranging from 26.5° to 30.1" C, from 

 June 22 to July 9, 191 1, at Tortugas, Florida. The medusa was kept in a 

 6-liter glass aquarium, the water being changed once in each 24 hours. 



Table 8. 



1 According to the formula y = 262(1 — O-66)*. 



