ON THE COMPOSITION OF CASSIOPEA XAMACHANA AND 

 THE CHANGES IN IT AFTER STARVATION. 



By S. Hatai. 



INTRODUCTION. 



Mayer (1914) reported that in Cassiopea the percentage of nitrogen 

 to the total solids remains constant during the entire period of starva- 

 tion; he infers that "no appreciable chemical change occurs in the 

 composition of its body, and that there is no appreciable selective use 

 of different substances at different times during the progress of star- 

 vation." This is remarkable, since the starving mammaUan body 

 reveals a totally different relation, owing to the rapid disappearance 

 of reserve substances, such as carbohydrates and fats, during the 

 earlier period of starvation, followed by a slow consumption of protein 

 substances later. Thus the starving mammalian body gives different 

 percentage values for the nitrogen at different periods of starvation, 

 especially in the earlier stages. 



The general anatomy of Cassiopea suggests that smce by far the 

 greater fraction of the body is represented by the reserve jelly-like 

 substance, while the amount of living cellular elements is small, 

 constancy in the percentage of nitrogen means that practically all the 

 nitrogen is represented by that of the jelly-like substance, which by its 

 relative abundance masks those chemical changes that may occur 

 within the epithelial elements. To test this point the experiments to 

 be described were undertaken. 



NORMAL GROWTH OF DIFFERENT PARTS OF THE BODY. 



Cassiopea may be divided into three distinct parts: (1) Mouth- 

 organs, (2) umbrella, and (3) velar lobes, which differ not only 

 morphologically, but also in their absolute weights and in the relative 

 amount of cellular and non-cellular constituents. It was, therefore, 

 thought desirable to study the normal growth of these parts in order to 

 determine whether the starving cassiopea loses weight uniformly or 

 whether the loss is dissimilar in the three parts concerned. Altogether 

 37nonTial examples of Cassiopea of various body- weights were examined, 

 and the results obtained are given in table 1. 



The individual records were plotted, together with the average 

 values, with a view to showing at a glance the extent of variation, and 

 are given in figure 1. 



Table 1 shows that the three parts increase in weight with the 

 increase of the entire body-weight, but the relative weights of these 



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