In their appearance and movements leucocytes strongly resemble amoebae: they are affected in a similar manner by heat, electricity, and drugs. Their resistance to the action of drugs varies somewhat in different animals. Those obtained from the blood of the newt, for example, are more resistant than those of the guinea-pig, and those of the female newt more resistant than those of the male, to the action of quinine.2 Heat and cold affect the movements of leucocytes in very much the same way as those of amoebae.

The movements of leucocytes, like those of amoebae, are of two kinds, viz. movements of the protoplasmic pseudopods, while the leucocyte remains in situ. The pseudopods in this instance are generally of a waxy look and knoblike form.

Secondly, movements of migration from place to place; these movements are accompanied, or accomplished, through the projection of numerous fine filaments.