78 



Papers from the Marine Biological Laboratory at Tortugas. 



Table 21 shows the decline in weight of the two halves of a disk of 

 Cassiopea xamachana starved in the diffuse daylight of the laboratory at 

 Montego Bay, Jamaica, 

 from February 27 to March 

 18, 1912, in water ranging 

 from 24.5 to 28 C. The 

 stomach and mouth-arms 

 of the medusa were re- 

 moved and the disk cut 

 into two nearly equal 

 halves, both of which were 

 maintained in one and the 

 same glass aquarium hold- 

 ing about 6 liters. The 

 water was changed once in 

 every 24 hours. 



8 9 10 n 12 13 14 15 16 17 18 19 

 Days X 

 Diagram illustrating Table 21. 



Table 21. 



1 According to the formula y = 

 According to the formula y - 



111.25(1- 

 125-93(1 



bo 



8 9 10 11 12 13 14 15 16 17 18 19 

 Days X 

 Diagram illustrating Table 22. 



0.089)'. 

 0.092)*. 



Table 22 shows decline 

 in weight of two regenerat- 

 ing specimens of Cassiopea 

 xamachana starved 19 days 

 in the dark, in filtered sea- 

 water, at temperatures 

 ranging from 27.5 to 30C., 

 from June 26 to July 15, 

 1 91 2, at Tortugas, Florida. 

 One was a disk deprived of 

 its stomach and mouth- 

 arms, and the other was a 

 medusa regenerating its 

 bell-rim, but with stomach 

 and mouth-arms intact. 



