Abstract
Amoeba proteus was immersed in various soaps, glycerine, dextrose, and ethylene glycol, and these substances were also injected into the ameba by means of the micrurgical apparatus. 1 Some of these substances were studied as possible vehicles and others for their specific effects.
The soaps used were the following sodium compounds: eleidate, laurate, linoleate, linolenate, myristate, oleate, pelargonate, ricinoleate, ricinstearolate, trihydroxystearate. In both the immersion and injection experiments the action of the soaps is the same, a solution of the plasmalemma. As far as can be seen, the internal protoplasm is not affected. These soaps dissolve the plasmalemma at rates which vary with the concentration.
In immersion experiments the plasmalemma disappears within a minute in concentrations of 0.1 to 0.5 per cent; in 24 hours in concentrations of 0.003 to 0.01 per cent; in 2 to 4 days in concentrations of 0.0001 to 0.002 per cent. A comparison of these soaps shows their relative toxicity to be the following: through 1 day, myristate > eleidate > oleate > linolenate > linoleate > laurate > ricinoleate > ricinstearolate > pelargonate > trihydroxystearate; from 2 to 5 days, myristate > laurate > ricinstearolate > oleate > eleidate, pelargonate > linolenate > linoleate > ricinoleate > trihydroxystearate.
In injection experiments it was found that the ameba could repair its dissolved plasmalemma after small injections of solutions of the variuus soaps, ranging from 0.1 to 1 per cent in concentration. No solution occurred after introduction of small amounts of 0.05 to 0.5 per cent; of moderate injections of 0.01 to 1 per cent; of large quantities of 0.005 to 0.25 per cent. A water effect was obtained with 0.001 to 0.02 per cent.
Get full access to this article
View all access options for this article.