68 



Papers from the Marine Biological Laboratory at Tortugas. 



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 



According to formula y_ = 497(1 0.0529)*. 



Remarks. Free-swimming algal cells were given off from these medusae every 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. 



11 medusae of Cassiopea starved 

 22 days in diffuse day-light 



s 



s 



O 200* 



100 { 



^"'-'..-. 



^S9j-t 



12 3 4 5 6 7 



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. 



i; Days 

 elapsed. 





 I 

 2 

 3 

 4 

 S 

 6 

 7 

 8 

 9 



Observed 



weight in 



grams. 



261.9s 



248.S 



243.9 



231-5 



21S.8 



192.7s 



185.7 



166.7 



158.3 



144.7 



Observed 



weight in 



grams. 



133.1 



128 



121.95 



112 



no. 2 



I0I.8 

 93-2 

 81.9 



Calculated 

 weight.' 



132.31 



123.66 



11S.28 



108.21 



102.61 



94-o6 



87.77 



82 



' According to the formula y = 262(1 0.66)*. 



