Mechanics of Locomotion in Amoeba

Locomotion is usually looked upon as being simpler in Amoeba than in any other animal.It is therefore not surprising that beginning with Rosel von Rosenhof in 1755 it has been very extensively studied in this form.As a result of this work many hold that the problem has been solved.They maintain that locomotion in Amoeba is the result of local reduction in surface tension and that it is essentially like movement in a globule of mercury produced by such reduction.(Berthold 1886, Biitschli 1892, Rhumbler 1898-1910, Hirschfeld 1909, McClendon 1912, et al.)There are unfortunately, however, a number of processes which are not in accord with this view.(1) The upper surface in many species moves forward in place of backward as it does in the movement of a globule of mercury.(Jennings 1904.)(2) Amoebae sometimes cut paramoecia in two; this requires many times as much energy as can be produced by changes in surface tension in systems like a globule of mercury.(Mast and Root 1916.)(3) Amoebae go away from regions of higher tempera- ture in place of toward them as would be expected if movement is due to local reduction in surface tension.To meet these difficulties contrac- tility, imbibition, adhesion, cohesion, solation and gelation have been suggested as factors in locomotion.