206 CARNEGIE INSTITUTION OF WASHINGTON. 



indebted to Dean Kozai and Professor Aso, of the agricultural college, for the 

 use of cliemicals and apparatus, without which many of the experiments 

 could not have been perfoi-mcd. The amount of work which I was able to 

 accomplish was largely due to Mrs. Harvey, who made observations of the 

 results of many of my own experiments during a temporary strain of my eyes. 



Changes in the Chemical Composition of Starving Cassiopea xamachana 

 {Preliminary Report), by S. Hatai. 



Mayer (1914) found that in Cassiopea the percentage of nitrogen to its 

 dried weight is constant during the entire period of starvation. Mayer 

 infers from this that "no appreciable chemical change occurs in the compo- 

 sition of its body-substances, and there is no appreciable selective use of 

 different substances at different times during the progress of starvation." 

 This is remarkable, since the starving mammalian body reveals a totally 

 different relation, owing to the rapid disappearance of reserve substances, 

 such as carbohydrates and fats, at an earlier period of starvation, followed by 

 a consumption of protein substances at a somewhat slower rate. In other 

 words, the starving mammahan body gives different percentage values of total 

 nitrogen at different periods of starvation, especially in its earlier stages. 



The anatomy of the medusa in general suggests that since a greater frac- 

 tion of the body is represented by the reserve jelly-like substance, while the 

 amount of living cellular elements is negligibly small, a constancy of nitrogen 

 may mean that practically all the nitrogen is here represented by that of the 

 jelly-like substance, thus totally masking those chemical changes which 

 occur within the living cell elements. To test this point, the following 

 experiments have been undertaken : 



As a first step, I have attempted to clear up the following points : 



(1) The normal decline in weight of different parts of Cassiopea. For 

 this purpose the Cassiopea was divided into three different parts— mouth- 

 arms, velar lobes, and umbrella. The object was to detennine whether the 

 starving Cassiopea loses weight uniformly in all parts of the body or whether 

 the loss is dissimilar in these three parts. 



(2) Percentage of water in these three parts. This was carefully studied, 

 using the normal Cassiopea as a check. In addition, the water-content of 

 the entire bod}^ of the normal Cassiopea of various sizes was also determined. 

 The object of these determinations was to obtain some general information 

 to be used for interpreting the chemical alterations following starvation. 



At the same time, 8 examples of Cassiopea of various sizes (29 to 152 

 grams) were subjected to a complete starvation. The method of starvation 

 and that of Aveighing were similar to those first used by Dr. Mayer (1914). 

 At the end of 21 days of starvation, each Cassiopea was divided into three 

 parts (mouth-arms, velar lobes, and umbrella), and each part was weighed 

 carefully and then dried at 98° C. to a constant weight for the determination 

 of water-content. 



Since the work is still in process, I am unable to present definite conclu- 

 sions, but can make the following verj'^ general statements : 



(1) The water-content of the normal Cassiopea is practically constant in 

 all sizes of animals examined (0.098 to 250 grams). The average per- 

 centage of water is 94.27 per cent. The constancy of water-content appears 

 to indicate that the body of Cassiopea is largely composed of the jelly-like 

 substance, the composition of which remains nearly identical throughout 

 the animal's life-cycle. This is a remarkable contrast to the water-content 

 of mammalian bodies of various ages, in which the younger individual gives 

 a higher percentage of water, and vice versa. 



