72 VITALISM AND SCHOLASTICISM 



stances which had up to this moment been its 

 slaves now become its masters and destroy it. 

 " This change is associated with alterations in 

 the mechanical and optical properties of the 

 protoplasm, which loses its viscidity and be- 

 comes opaque, having undergone a process of 

 de-solution; for the water it contained is now 

 held only mechanically in the interstices of a 

 network, or in cavities of a honeycomb, while 

 the solid forming the residuum has a refractive 

 index of a little over 1.6. Therefore, it only 

 regains its full transparency when the water is 

 replaced by a liquid of high refractive index, 

 such as an essential oil or phenol. A similar 

 change may be effected by pouring white of 

 egg into boiling water or absolute alcohol, and 

 is attended with the same optical results."* 



Such, then, are the chief characteristics 

 revealed by our study of the amoeba. It 

 moves, it responds to stimuli, it breathes and 

 it feeds, it carries on complicated chemical 

 processes in its interior. It increases and 

 multiplies and it may die. 



These observations are not only true of the 

 single-celled organism but of the multicellular 

 and they are equally applicable to the animal 

 and to the plant. 



* Hartog. 



