ss 



Papers from the Marine Biological Laboratory at Tortugas. 



were all growing at a healthy rate, as is readily seen by comparing the 

 specific amounts of regeneration with those of July 6. Individuals with 

 two, three, four, and five arms cut away are going at similar rates, although 

 showing irregular fluctuations. A point of some importance is that there 

 is a greater difference in regeneration rates between the two individuals 

 with three arms cut away than between any others of the series having 

 lost from two to five mouth-arms. Those with six and seven removed 

 arms still lead in the rate of regeneration. The two with four alternate arms 

 cut away are going at about the same rate as the two with four consecutive 

 mouth-arms removed. 



The experiment was closed after 38 days, at which time the longest 

 buds were slightly less than 9 mm. in length. These were produced by 

 the medusae in which four and five arms had been removed, which were 

 among the largest individuals of the series. Those with one and two cut 

 arms were regenerating at about equal rates. The two individuals with 

 three removed arms showed a great difference between their average regen- 

 eration rates. Those with four arms removed were regenerating faster than 

 those that had five arms cut away. Those with six and seven cut arms 

 led the series, but, as mentioned above, these were the smallest individuals. 

 The two with four alternate arms removed were perceptibly behind those 

 with the four adjacent ones cut away. 



Table 2. — Average specific amounts of regeneration from medusa: zvith their mouth- 

 arms removed. 



• Four alternate mouth-arms were removed, in all others adjacent arms were cut away, 

 t No regeneration at all from one arm-stump. 



Table 2, as a whole, indicates a condition of individual variation and 

 fluctuation in the regeneration rates rather than anything else. It should 



