CHARLES F. LYTLE 323 



9-23 C 



H y d r a n t h s 



O O- o- 



Fr u St ul es 



o o o o- 



Medusae 



10 12 14 16 18 



WEEKS 



Fig. 6. Budding pattern of 13 polyps reared on a water table with the 

 temperature rising slowly from an initial 19 to a maximum of 23 and re- 

 turning to 19 at the end of 16 weeks. Values on the abscissa represent the 

 number of buds of each type produced per colony. 



as in the absolute and relative numbers of buds of each type pro- 

 duced at the various temperatures. 



My temperature experiments also indicate the existence of cer- 

 tain interactions between the three budding processes. Figure 7 il- 

 lustrates the relationship between hydranth budding and medusa 

 budding. At all three temperatures there was an initial rapid rise in 

 the number of hydranths per colony, medusa buds appearing only 

 after the production of hydranths ceased or greatly declined. Me- 

 dusa buds were produced earliest at 20' when the total number of 

 hydranths produced was the smallest. Medusa buds were produced 

 latest in the 19-23 colonies when the total number of hydranths 

 was the greatest (Table 1). When subjected to statistical analysis 

 ( analysis of variance ) , differences in the time of appearance of the 



