CHARLES F. LYTLE S31 



dusa buds always appear after growth has decHned or stopped, 

 and because the abbreviated phases of growth at 20° and 27" are 

 associated with the early formation of medusa buds. The longer 

 growth phase at 19-23 is associated with a delay in the forma- 

 tion of medusa buds. Also hydranth budding is the least affected of 

 the three types of budding by lowered nutritional level. A similar 

 inverse relationship between growth and medusa budding was 

 found in Hydr actinia by Hauenschild and in Obelia by Grell (11). 

 Crowell (5) also found a definite order of priority in the utiliza- 

 tion of nutritive substances among the several growth zones of 

 Campanularia when overall growth was experimentally limited. 

 Significantly, he observed that the formation of gonangia ap- 

 peared to require a high nutritive level. 



Medusa budding appears to limit frustule production since in 

 all cases the appearance of medusa buds is preceded by a decline 

 in frustule budding. The production of frustules always reached an 

 initial peak after the completion of the initial growth phase and de- 

 clined prior to the appearance of medusa buds. This decline in 

 frustule production was most marked in the 19-23 colonies which 

 produced the greatest number of medusa buds, and least pronounced 

 in the 20" colonies where the fewest medusae were produced. In 

 cultures of high temperature frustules which produced no medusa 

 buds, there was no subsequent decline in the rate of frustule pro- 

 duction after the initial maximum was reached. The relationship 

 between hydranth budding and frustule budding was less clearly 

 demonstrated, but there were some indications of a similar inter- 

 action between these two processes also. 



These experiments clearly demonstrate that temperature between 

 20° and 27° is not a limiting factor in the production of medusa 

 buds by isolated colonies in culture if sufficient food is provided, 

 contrary to the observations of Reisinger (20, 21) and McClary 

 (14). Studies on nutrition have shown that lowering of the feeding 

 rate within this temperature may diminish and/ or greatly delay the 

 production of medusa buds. 



Experiments on the effect of various nutritional levels on the 

 budding processes of isolated colonies demonstrate that the three 

 budding processes are affected differentially by increased feeding 

 rates. At very low feeding rates, medusa budding may be reduced 



