99 



The same determinations are made with animals that have been 

 starving for six months. All dry components have dimished, 

 except for the ..insoluble carbohydrates"; the ratio of C : N 

 which was 1 : 5.1 at the beginning, appears to be 1 : 5.6. so 

 that the nitrogenous constituents have diminished more than 

 the carbon compounds. 



The loss of weight is determined for every month and in 

 combination with the above mentioned data he finds that the 

 animal loses on the average 0.0155 mgr. C and 0.00327 mgr. N 

 in an hour. 



The author then determines the oxygen consumption. This 

 appears to be dependent on three factors : hght (!), temperature 

 and physiological condition. The temperature relation is quite 

 clear; not clear however is the influence of light and the fact 

 that animals which have been starved for three month consume 

 about twice as much oxygen as before starvation. 



Carbon is ex-(se-)creted in four different ways: 



1. As COj, partly dissolving in the sea water, partly disap- 

 pearing in the air. 



2. As a volatile hydrocarbon, probably CH4 (methene). 



3. As formed material, e.g. as mucus and cells. 



4. As complex watersoluble carbon-compounds. 



These four factors are all studied quantitatively. CO2 and the 

 hydrocarbon are very regular, the two other factors very irre- 

 gular. The respiratory quotient is very high in the beginning 

 (about 3.8). later on it is about 0.8. 



The total C-production is now determined and the relative 

 importance of the three groups. The fresh animals secrete 1.64 

 times as much C. The nitrogenous excretion is also studied. 

 The production of nitrites and nitrates is quite regular, but the 

 K j e 1 d a h 1-N shows no regularity whatsoever. Average values 

 are used. The irregularity may partly be due to the excreted 

 cells which come very irregularly. 



Since in the combustible excreted gases more H is present 

 than agrees with the formula CH4, it is evident, that free Hj 

 is also excreted in small amounts. 



Thp. quantity of „ volatile acids" and ..volatile alkalies" excreted 

 is also determined. 



From all these data the author tries to get an impression 

 of the ..total metabolism". Here he enters into the field of 

 speculation. 



His ..point de depart" is the total N-metabolism. figured 

 from the N-excretion. On the assumption that this represents 

 the protein consumption, he finds the corresponding C-produc- 

 tion. The remaining C is now divided up in several ways, an 

 ingenious and clever system, based on various assumptions and 



facts. 



Let us first consider the fundamental figure of the whole 



