LI AND LENHOFF 



443 



"short tentocled 

 bud" stage 



"long tentocled 

 bud" stage 



feed to 



maturity 



Fig. 2. Stages of budding Hydra. 



and RNA measurements were made without separating these macro- 

 molecules from the rest of the cellular components. Thus, the DNA 

 and RNA values also include the smaller species of these molecules. 

 The DNA, RNA, and protein were assayed, using the diphenyla- 

 mine (1), orcinol (5), and Lowry (4) methods respectively. The 

 protein, DNA, and RNA values for Hydra before feeding (not 

 shown on this figure ) were about half that of their respective values 

 at 12 hours. Thus, on feeding, a doubling in all of these components 

 occurred because of the ingested protein, DNA, and RNA of the 

 shrimp. During the next 72 hours, however, these macromolecular 

 components decreased slowly, while the DNA protein ratio re- 

 mained relatively constant. The changes observed probably resulted 

 from at least two factors: (a) degradation of the ingested food, and 

 (b) the synthesis of Hydra cellular components. 



In Figure 4 are shown the DNA protein ratio of Hydra in the 

 long-tentacled bud stage and that of the same animals 48 and 72 

 hours later when the buds have detached from the parent. (The 

 protein content of the bud was about one third that of the parent. ) 



