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Puget Sound Marine Sta. Pub. 



Vol. 1, No. 22 



seem to be decidedly more acid during the afternoon. There is some 

 suggestion of greater acidity in the growing portions of Nereocystis, sug- 

 gesting a possible relation to Schley's (Bot. Gaz, 5Q\ 480-489. 1913) 

 findings in angiosperm seedlings, but the results are not conclusive. 



Table 1. Showing relative acidity at different times of the day. 



Green Algae Where 



3-6:30 A.M. 10-11:30 AM. 2-4:30 P.M. Collected 



Enteromorpha llnza 0.326 0.2325 0.1925 Shore 



Ulva lactuca 0.413 0.226 0.316 Shore 



Cladophora arcta 0.78 0.42 * Shore 



Brown Algae 



Agarum flmbrlatum, blade .... 2.31 2.475 2.35 Shore 



Agarum fimbriatum, midrib .... 0.72 1.34 1.06 Shore 



Desmarestia ligulata 0.75 0.58 0.493 Dredged 



Desmarestia aculeata 0.73 3.10 0.725 Dredged 



Costaria costata 0.253 0.176 0.25 Shore 



Fucus evanescens, vegetative . . 0.83 0.88 1.28 Shore 



Fucus evanescens, receptacles... 0.16 0.13 0.22 Shore 



Leathesia difformis 0.273 0.15 0.13 Shore 



Nereocystis luetkeana, holdfasts. 0.371 1.02 0.32 Shore 



Nereocystis luetkeana, stipes .... 0.26 0.735 0.62 Shore 



Nereocystis luetkeana, bulbs . . 0.296 0.313 0.29 Shore 



Nereocystis luetkeana, fronds.. 0.262 0.156 0.10 Shore 



Laminaria saccharina 0.286 0.143 0.303 Shore 



Red Algae 



Callymenia phyllophora 0.51 0.48 0.57 



♦Ceratothamnion pikeanum .... 0.36 0.36 0.293 Shore 



Dasyopsis plumosa 1.03 0.316 0.492 Shore 



Fauchea laciniata 0.496 0.76 0.47 Dredged 



Gigartina mamillosa 0.296 0.42 0.332 Shore 



Gigartina radula 0.326 0.225 0.18 Dredged 



Gloiopeltis furcata 0.323 0.383 0.266 Shore 



Halosaccion glandiforme 0.F8 0.346 0.29 Shore 



Iridaea laminarioides 0.423 0.243 0.271 Shore 



Nitophyllum latissimum 0.77 0.86 0.23 Dredged 



Nitophyllum ruprechtianum .... 2.36 2.18 2.00 Dredged 



*Polysiphonia Sp 0.45 0.40 0.31 Shore 



*Ptilota pectinata 0.58 0.48 0.62 Shore 



Rhodymenia pertusa 0.153 0.24 0.25 Dredged 



*Rhodomela larix 0.80 0.61 0.45 Shore 



♦Results only approximately correct since juice was very red in color. 



Table 2. Shotving acid determinations for Nereocystis luetkeana about 

 of nearly 3 hours during the 24. 



Time — Holdfast 



4-5 A. M 0.371 



6:45-7:30 A. M 0.40 



9:30-10:15 A. M 1.02 



12:30-1 P. M 0.38 



4:10-4:45 P. M 0.32 



6:30-7:30 P. M 0.29 



9-10:15 P. M 0.47 



Midnight-2 A. M 0.40 



Table 3. Shorting acid determination for Fucus evanescens at intervals 

 of nearly 3 hours during most of the 24. 



6 A. 

 Vegetative .83 

 Receptacles .16 



M. 



