MARINE BIOLOGICAL STATION AT PORT ERIN. 65 



" The variations in reaction have now, during periodical 

 visits to Port Erin and by means of samples of water sent over 

 to Liverpool, been followed throughout the circuit of the year. 

 The hydrogen-ion concentration has also been carefully con- 

 trolled by the electrode method by Dr. Prideaux, and the results 

 are now being put together for publication. 



" (III.) The respiratory exchanges in Crustacea and fishes, 

 which had previously been observed over short periods not 

 exceeding 48 hours, have now been estimated over periods of 

 several weeks, and in some cases lobsters have been kept under 

 experimental observation for several months. This work 

 demands a great deal of labour, both in making the daily 

 chemical experiments, and also afterwards in calculating out 

 the results ; but the task is now nearing completion and 

 important data will be obtained thereby as to habits of life 

 and the daily demand for nutrition in such animals. The daily 

 output of carbon-dioxide and uptake of oxygen have been 

 determined, and the quantities of protein, fat, and carbohydrate 

 in the total animal of given body- weight, at the beginning and 

 end of the prolonged period of the experiment, have now been 

 carefully estimated. 



" The main part of the expense of the above series of 

 investigations has been met by grants from the Trustees 

 of the Percy-Sladen Memorial Fund, to whom a full report 

 upon the details of the work with statement of results will be 

 presented in due course." 



Plankton Investigations at Port Erin. 



The plankton work has been carried on in much the same 

 way for the last six years, with the help of various Assistants, 

 from the S.Y. " Runa " out at sea during the Easter and 

 Summer vacations, and across Port Erin Bay in small boats 

 during the rest of the year. 



