SEA-FISHERIES LABORATORY. 405 



the metabolic exchanges are so slow that a period of several 

 weeks' duration becomes necessary, in order to show the 

 result clearly. When sufficient time is given, however, 

 the proteins become much reduced, and the loss is suffi- 

 cient to account for all the energy required for the 

 metabolism of the fasting animal. 



In conclusion, the results of the examinations of the 

 tissues of the four animals are given; those in the case of 

 the lobsters may be compared with the similar results in 

 the succeeding paper. It is noteworthy that carbohydrate 

 is absent, but, strange to say, even in normal lobsters the 

 amount of glycogen or other carbohydrate is excessively 

 low ; whether this is a seasonal result, or is always the 

 case, we have not at present determined. 



Immediately at the end of the experiments the 

 animals were weighed, killed, and preserved by placing 

 in excess of absolute alcohol. After some weeks, the 

 alcohol was separated and taken down to dryness, the soft 

 parts were then separated, dried, and reduced to a powder, 

 the hard parts were similarly treated, and then the soft 

 parts and hard parts were thoroughly mixed and incor- 

 porated by grinding up together in a mortar. The mixed 

 powder was then dried in a desiccator over sulphuric acid, 

 and weighed, so giving, on addition of the dry weight of 

 the alcoholic extract, the total dried weight as shown in 

 the table. The dried powders from the four animals were 

 preserved for the analyses in dried glass-stoppered wide- 

 mo ut lied bottles. The figure given as protein is the total 

 nitrogen figure from a Kjeldahl multiplied by the factor 

 6'25. It is probably a little too high, but there is very 

 little nitrogen present other than protein nitrogen. 



Fats were determined in the usual way from Soxhlei 

 extractions with ether. Glycogen was absent throughout. 

 "Extractives" means alcoholic extractives less fats. The 



