106 



Papers from the Department of Marine Biology. 



of nitrogen is notably high for the final starved body-weight when com- 

 pared with that in the control with a similar body- weight (table 7), but it 

 is much lower for the initial unstarved body-weight, as will be seen from 

 the extremely low percentage of nitrogen when calculation was made in 

 respect to the initial body- weight instead of the final (see table 7, sixth 

 column) . This indicates clearly that during starvation the animal has 

 utilized a considerable amount of the nitrogenous substances — a conclu- 

 sion which is important, as it answers the main question before us and 

 brings Cassiopea in line with the vertebrates in its reaction to starvation 

 conditions. It is highly probable that some fraction of the nitrogen uti- 

 lized may represent that of the cellular substance. Mayer (1914) noted, 



Table 7. — Percentage of nitrogen in the normal Cassiopea compared with that 

 in the starved Cassiopea. 



'Average of two cassiopeas 



^Data given by Mayer (1914). 



from the sections made on the starved cassiopea, not only reduced cell 

 size, but also many degenerated cell-bodies, and there was evidence also 

 of a complete disappearance of some of the cellular elements. Mayer 

 found also a vacuolated condition of the gelatinous substance accom- 

 panied by a greater loss of the muscular tonus. The chemical altera- 

 tions noted above accord with his findings. 



Mayer concluded that the percentage of nitrogen in the solids is 

 independent of the period of starvation and is practically identical with 

 that obtained from the non-starved cassiopea. I have, however, 

 found, as stated above, that starvation tends to increase not only the 

 percentage of nitrogen in the solids, but also that the absolute amount 

 of nitrogen shows an increase when the starved cassiopeas were com- 

 pared with the normals having the same body- weight. The discrep- 

 ancy between the conclusions drawn by Mayer and by myself is, I 

 believe, due to the fact that Mayer's observations were limited to the 

 larger cassiopeas (body-weights over 100 grams) in which the percent- 

 age of nitrogen in the solids shows little variation following the large 

 variations of the body-weight, while the variations in the nitrogen are 

 quite noticeable in the cassiopeas of smaller size. I may add here that 



