Abstract
1. Locomotion. This does not occur to any appreciable extent in distilled water, acids, bases, KCN, H2O2, the leucobase of methylene blue, sugar, alcohol, papaverine hydrochloride and quinine (the alkaloid, not its salt), when Amoebae are immersed in solutions of them in the concentrations mentioned. It does occur for varying lengths of time in certain concentrations of all the neutral salts used, and in an acid or base when a neutral salt is added. Salts which because of hydrolysis give an acid or basis reaction impede locomotion, depending on the degree of hydrolysis and the concentration.
2. The surface of Amoeba in various solutions. It is very adhesive in acids of a concentration of N/I to N/40,000, in salts which because of hydrolysis give an acid reaction, and in the leucobase of methylene blue. It is sufficiently adhesive in neutral salts in suitable concentrations to permit attachment to the substratum. Without such attachment, locomotion is impossible, therefore one of the conditions for locomotion is an adhesive surface, but the latter condition alone is no indication that locomotion will take place. The surface of Amoeba is not adhesive in sodium or potassium hydroxide, or in salts which because of hydrolysis give a basic reaction, and it is only indifferently adhesive in H2O2 and in the non-electrolytes and alkaloids used. It contracts in acids and considerably more in bases, although the surface is dentate in acids and smooth in bases, but undergoes no significant change in certain concentrations of neutral salts. The ectoplasmic surface ruptures readily in strong solutions of bases and salts. The time required varies with the concentration.
The ammonium salts used induce intermittent ejections of the endoplasmic contents, hence there is not a single rupture following which all the endoplasm is extruded, such as happens after a short or long period of immersion depending on the concentration in sodium or potassium hydroxide, or the salts used. The ectoplasmic surface is seen as a distinct morphological unit after it has ruptured in the reagents mentioned. In sodium or potassium hydroxide, it is preserved for varying lengths of time depending on the concentration, dissolving rapidly in strong solutions and more slowly in weak solutions. In salts, especially the neutral salts, it is preserved for several days, and is seen as a sort of vesicle containing the nucleus, some food-vacuoles, and a few crystalline particles attached to its inner surface.
3. The endoplasm of Amoeba in the solutions used. In acids and in the leucobase of methylene blue, it undergoes violent and unco-ordinated streaming. The streaming is conditioned in its violence and inco-ordination by the concentration of the acids, and by the degree of oxidation of the leucobase. It is more violent the stronger the acid and the less oxidation that has occurred in the leucobase at the time of immersion. Distilled water saturated with CO2 and HCN in fairly dilute solutions, as well as strong solutions, constitute media in which this does not occur. Streaming is almost immediately stopped in CO2 and markedly impeded in HCN. In sodium or potassium hydroxide, KCN, H2O2, non-electrolytes and alkaloids, streaming is very slow even in very dilute solutions and stopped altogether in strong solutions. The inclusions of the endoplasm dissolve when Amoeba is immersed for some time in KCN and HCN, in alcohol and certain alkaloids in the concentrations mentioned, and in the leucobase of methylene blue. The food-vacuoles are distended in the solutions used of HCN, alcohol, ammonium salts, NH4OH, the leucobase of methylene blue and somewhat in LiCl, but are ejected only in NH4OH and ammonium salts, and with considerable endoplasm in many instances. The crystalline inclusions, which are ordinarily enclosed within a pellicle, i.e. each inclusion or crystal within a separate pellicle, come together in varying numbers within a common vesicle in certain solutions. There are usually two, three, or more such vesicles in a given specimen, each of which contains a dozen or more of such crystals. This sort of crystal aggregation occurs in KOH, N/4000 ; NH4OH, N/2000; NaHCO3, N/400 ; LiSO4, N/300, and a mixture of potassium nitrate, sulphate, and acetate, N/300. They may occur in other concentrations, but the above concentrations were the ones used when such aggregation was observed.
4. Time of inactivation or death of Amoeba in the various solutions. The time varies depending on whether or not the Amoebae were washed in distilled water (being shorter in the latter instance) as well as on the concentration. The following is for Amoebae that were washed in distilled water before immersion in the various solutions : (a) Acids, N/100 and N/1000, 7 minutes to 1 hour. (b) Sodium and potassium hydroxide, N/100 and N/200, 20 seconds to 1 minute; N/500 and N/1000, 2 to 3 hours ; N/2000, 20 or more hours ; N/4000, 48 or more hours, (c) KCN, molecular, made neutral to phenolphthalein by the addition of HCN, 12 minutes ; KCN without the addition of HCN, 2 minutes ; KCN, N/100 (made neutral as above), 2 or more hours ; KCN, N/100, without HCN, 1 hour to 1½ hours, (d) Salts: NH4Cl, N/300, 32 hours ; NaCl, N/300, 266 hours; NaCl, N/100, 124 hours ; a mixture of equal parts of KCl, N/500 with KOH, N/4000, 64 hours ; a mixture of equal parts of KCl, N/500 with HCl, N/6000, 81 hours ; CaCl2, N/300, 211 hours ; NaCl and CaCl2 mixed in equal parts, N/300 each, 266 hours ; NaCl and CaCl2, N/100, mixed in equal parts, 124 hours ; LiCl, N/300, 116 hours ; NaCl, KCl, and NH4Cl, N/500, mixed in equal parts of each, 125 hours ; BaCl2, SrCl2, and CaCl2, N/500, mixed in equal parts of each, 56 hours ; NH4NO3, N/300, 33 hours; NaNO3, N/300, 92 hours ; KNO3, N/300, 88 hours; RbNO3, N/300, 62 hours ; Ca(NO3)2, N/300, 116 hours ; NaNO3 and Ca(NO3)2, N/300, mixed in equal parts of each, 119 hours ; NaNO3, KNO3, and Ca(NO3), N/300, mixed in equal parts of each, 132 hours ; (NH4)2SO4, N/300, 32 hours ; Na2SO4, N/400, 60 hours ; Li2SO4, N/300, 30 hours ; LiCl and Li2SO4, N/300, mixed in equal parts of each, 30 hours ; Na2SO4, K2SO4, and (NH4)2SO4, N/400, mixed in equal parts of each, 124 hours ; NH4C2H3O2, N/300, 4 hours ; NH4HCO3, N/300, 2 to 3 hours ; NaC2H3O2, N/400, 35 hours ; NaHCO3, N/400, 93 hours ; NaC2H3O2 and KC2H3O2, N/300, mixed in equal parts of each, 52 hours; NH4Cl, NH4NO3, and (NH4)2SO4, N/300, mixed in equal parts of each, 14 hours ; NH4NO3) (NH4)2SO4, and NH4C2H3O2, N/500, mixed in equal parts of each, 3 hours ; NaCl, NaNO3, and Na2SO4) N/300, mixed in equal parts of each, 92 hours ; NaCl, Na2SO4, and NaC2H3O2, N/300, mixed in equal parts of each, 55 hours.
5. The effect of acids. They seem to make the surface of Amoeba gelatinous and adhesive, and this condition obtains in very dilute solutions, e.g. N/20,000. The effect is reversible if the Amoebae are transferred to culture fluid or a weak neutral salt solution before the action becomes too prolonged. HCN is different in its action on Amoeba from the other acids used. It is similar in effect to alcohol and KCN when the latter is made neutral by the addition of HCN. Distilled water saturated with CO2 apparently causes a rapid entrance of fluid, so that the granular endoplasm is surrounded by a broad hyaline area.
6. The effect of bases. Sodium and potassium hydroxide seem to liquefy the surface of Amoeba so that it is inadhesive and very susceptible to rupture. Ammonium hydroxide apparently neither liquefies nor gelates the surface, but evidently passes rapidly into the cell causing marked changes in the endoplasm, which is manifested chiefly in the eruptive character of streaming and the ejection from time to time of the food-vacuoles and other endoplasmic contents. The effect is apparently dependent, as Jacobs4 indicates, on the absolute concentration of the free base present.
7. The effect of salts. All of the neutral salts used are for varying lengths of time depending on the concentration and the salt favourable to normal activity. The cations, in so far as the effect of salts is ionic, produce marked effects, while the anions are relatively inactive, although it appears that the chlorine ion is less toxic than the nitrate ion, and the nitrate ion than the sulphate ion. The cations differ in their action, and likewise the anions and univalent and bivalent ions also differ among themselves as well perhaps as a group. The sodium ion seems less toxic than lithium, and lithium than potassium, potassium than rubidium, and rubidium than ammonium. Calcium is less toxic than barium, strontium, or magnesium. The carbonate and acetate ions are more toxic than the chlorine, nitrate, or sulphate ions, and the acid carbonate less toxic than the basic carbonate.
8. The effect of oxidising and reducing agents. Hydrogen peroxide appears to induce an irreversible permeability. The leucobase of methylene blue makes the surface of Amoeba gelatinous and adhesive, and stops almost immediately all activity. The endoplasm becomes hyaline, and at death the Amoeba is seen as a spherically lobose vesicle.
9. The effect of non-electrolytes. Cane sugar and glucose impede locomotion depending on the concentration. No significant abnormalities were noted. Alcohol seems to liquefy the surface and make the cell permeable. The endoplasm becomes after a time gradually hyaline. Streaming is impeded although at times it is eruptive and unco-ordinated.
10. The effect of alkaloids. The alkaloidal salt, quinine hydrochloride, causes no apparent abnormalities, but the alkaloid, quinine, and papaverine hydrochloride prevent locomotion and reduce streaming. The endoplasm in the latter solutions becomes partially hyaline. The surface of Amoeba is apparently made more permeable than normally, and also partially liquefied.
11. The effect of the chemicals used on enucleated Amoebae. Enucleated Amoebae disintegrate more readily in all of the solutions used than nucleated ones. The PH of the endoplasm seems also to be lowered in enucleated Amoebae.
12. The ectoplasmic surface of Amoeba is elastic. Mechanically induced pseudopods that do not contract are prevented from contracting by adhesion to the substratum. Protoplasm from a ruptured Amoeba was not observed to form a new surface membrane on coming in contact with the surrounding medium. Torn ectoplasm heals by a drawing together of the torn surface at the ruptured place. The endoplasm extruded during a temporary rupture takes no part in closing the rupture.