NUTRITION OF OYSTERS: GLYCOGEN FORMATION AND STORAGE. 



155 



throughout the experiment by bubbling air from an aspirator bottle through glass tubes 



reaching to the bottom of the dish. At the end of a period, varying from two to five 



days, the entire shell contents of the oyster were dried down and analyzed. Analyses, 



for comparison and control, were made on oysters taken from the same source as those 



used for feeding with sugar, but analyzed at the beginning of the experiment; and also 



analyses of oysters from the same lot kept meanwhile in aerated sea water containing 



no sugar. In one experiment a further control consisted in the analyses of oysters 



having the same origin as the others, but kept during the time of the experiment in a 



wire cage suspended in the water near the Government docks at Woods Hole Harbor. 



Here with garbage and animal and plant life in very great abundance, feeding conditions 



were about as rich as could be obtained. The results of the experiments are shown in 



Table 2. 



Table 2. — Formation of Glycogen from Dextrose. 



Experi- 

 ment 



No.o 



Oys- 

 ters 

 used. 



Average 



weight 



of oyster. 



Treatment of oysters. 



Ash in 

 dried 

 meats. 



Glycogen 

 in dried 

 meats. 



Glycogen 



in ash- 

 free solids. 



Gravis. 



Analyzed at beginning of experiment to be compared with treated 

 oysters of Nos. 2. 3, and 4 



In sea water, sp. gr. 1.023. containing^ per cent of dextrose during 48 

 hours. 



In sea water, sp. gr. i.ois. containing 14 per cent of dextrose during 48 

 hours 



In running sea water in aquariiun for 15 days, then treated exactly 

 like No. 3 



Analyzed as soon as brought from beds, to be compared with Nos. 6, 

 7. 8, and 9 



In sea water, sp. gr. 1.015, containing '4 per cent dextrose during 48 

 hours. 



In sea water, sp. gr. 1.015, with no dextrose, treated like No. 6 during 

 60 hours 



Taken from running sea water in aquarium at time No. 6 ended. 

 Control of Nos. 6 and 7 



Kept in wire cage in Woods Hole Harbor during 50 hours before analy- 



GROUP m. 



Analyzed as soon as brought from beds, to be compared with Nos. 11, 



12, and 13 



In sea water, sp. gr, 1.015, containing yi per cent crude glucose during 



48 hours 



In running sea water in aquarium 48 hours, then treated with glucose 



like No. II, 72 hours 



In sea water, sp. gr. 1.015, without sugar during 76 hours. Had been 



in aquarium 48 hours. Control for No. 12 



Per cent. 

 36-45 



33-70 



39-45 

 23-68 



25-30 

 21-65 

 24-35 

 30.08 

 30.87 



35-57 



14.86 

 19.00 



23- 12 



GROUP IV. 



Analyzed as soon as brought from beds, to be compared with Nos. 15 

 and 16 



In sea water, sp. gr. 1.022, containing K per cent dextrose during 65 

 hours 



In sea water, sp. gr. 1.022, without dextrose during 67 hours 



18.33 

 19.99 



Per cent. 

 2.77 



4- II 



4-38 



8.55 



9-47 

 11-30 

 9-43 

 8.63 

 9.69 



9.28 

 12.08 



12-75 

 10.05 



22.77 

 21. 26 



Per cent. 



4-37 



6- 20 



6-21 

 II-2I 



12. 70 

 14-43 

 12.47 

 12.36 

 14-02 



12.47 

 14.19 



15-74 

 13-07 



26.55 



27.90 

 26.33 



o All oysters used in experiments of the several groups came from the same beds at the same time. 



These results show clearly that glycogen may be formed in the oyster from dextrose, 

 while experiment No, 9 shows that even richest feeding in excellent normal conditions with 

 abundant tide flow did not cause as much glycogen formation as that obtained by treat- 

 ment during the same time with a 0.25 per cent dextrose solution and under somewhat 

 adverse conditions at that. The oysters were crowded into a dish in water that was not 

 changed throughout the time of the experiment. Indeed, experiments Nos. 7 and 8, com- 

 pared with No. 5, show how adverse conditions in the laboratory may tend to lower the 



