THE ANIMAL A MACHINE 



167 



Fig. 65. Tortuous Path of a Drop of Heavy Oil (Chloroform) on a 



Shellac Plate 



Such an oil drop moves around in much the same manner as an amoeba 

 through the extension of protrusions; compare figure 61. In the Amoeba 

 the direction in which these pseudopodia are extended is frequently varied. 

 Consequently, the pathway over which the animal travels is a very tortuous 

 one. The same is true for the pathway of a moving oil drop as shown in 

 this figure. The pathway is rendered visible through the dissolution of 

 some of the shellac of the underlying shellacked plate. (One-half natu- 

 ral size.) 



P 



Fig. 66. Diagrams of the Various Amoeba-like Forms Which Can Be 



Produced by Oil-Drops 



The shape of the oil drop depends on the kind of oil used and on the 

 addition of various substances to the watery solution in which the drop is 

 floating. Almost any outline of one-celled animals can thus be imitated 

 by artificial methods. (Natural size.) 



