-~ll-
accumulated none.
The metabolism of the living algae,
there-
fore, had something to do with the uptake of radioactive
particles.
From decay curves it appears that this activity
could be due to one or more of the following isotopes:
Rute,
gr?
cgh37,
cet 44 |
and sr??,
Radiochemical analyses of this material are in progress.
The decay curves also show the same slopes in the algae as
in the solutions, indicating no selective uptake by the algae.
When ce 144 was added to the solution of mixed fission products,
uptake by the algae was very rapid.
Other experiments with circles of the alga Ulva Lactuca
and Nereocystis leutkeana,
incubated in solutions of mixed
fission products from Engebi sand, showed that five per cent of
the total activity in solution was taken up per gram of Ulva
in 12 days and 10 per cent by Nereocystis in three days.
These
experiments will be continued.
Electron micrographs of the filtered Engebi sand solution
were prepared.
No particles were found in suspension, showing
that there was a true solution rather than a colloidal suspension of the radioactive particles.
B.
Food cycling experiments with invertebrates
In the experiment with the water movement by the horse
mussel, Modiolus modiolus, the presence of suspended matter