SEA-FISHERIES LABORATORY. 403 



The added time-intervals for which the oxygen intake 

 and carbon-dioxide output were estimated amount to 

 27 days, 16 hours, 25 minutes, and the oxygen used up 

 totals 17372 grams, and output of oxygen in carbon- 

 dioxide to 16"789 grams. The daily quantity of oxygen 

 exchange is very approximately 0'6 gram. 



The weight of the animal at the start could not be 

 taken, but as it was 370 grams at the finish, it may be 

 taken roughly as averaging 400 grams during the 

 experiment. The result is, therefore, that an octopus 

 weighing 400 grams consumes 0'6 grams of oxygen daily, 

 and the respiratory quotient is practically unity. This 

 shows a much higher metabolic activity for this species 

 of animal than for a lobster, and one that is approximately 

 equivalent to that of the fish. For, if the metabolism be 

 taken as proportional to the surface and an octopus of 400 

 grams uses up 0'6 gram of oxygen daily, then one of 250 

 grams will use up an amount of 0'46 gram, while the fish in 

 Experiment III., weighing 240-270 grams used up 

 0.45 gram daily, the corresponding figure for the lobsters 

 lies at about one-third of this amount, namely, 016 to 

 018 gram daily. 



In a free condition and when feeding the metabolism 

 would naturallv be higher, but even if the figures be 

 doubled, an extraordinarily low metabolism is revealed. 

 For, a wet weight of about three grams of animal matter 

 daily would appear to be enough to maintain a fairly large 

 fish or octopus, and one-third of that amount to maintain 

 a lobster. When feeding, such animals almost certainly 

 consume many times this quantity of food daily, and 

 hence it becomes obvious that the greater portion of the 

 food supply is utilised for intermediate metabolism, and 

 for the production of the organic matter required in their 



