TORGf. To 



PART I 



SECTION I 

 PROTOPLASM 



THE first step in the study of physiology must be to acquire as 

 clear and definite a conception as possible of the nature of 

 protoplasmic activity in its most simple and uncomplicated 

 form, for in this way an idea of the essential and non-essential 

 characteristics of life may best be gained. 



I. Structure. Protoplasm is a semi-fluid transparent viscous 

 substance. It usually occurs in small individual particles 



(a) 



(c) 



FIG. 1. (a) Foam structure of a mixture of Olive Oil and Cane Sugar ; (6) Reticu- 

 lated^stiucture of Protoplasm ; (c) Reticulated structure of Protoplasm in 

 the cell of an earth-worm (after BUTSCHU). 



CELLS more or less associated, but it may occur as larger 

 confluent masses PLASMODIA. 



Sometimes protoplasm seems perfectly homogeneous, but 

 generally a reticulated appearance can be made out even in the 

 living condition (fig. 1), and from this it has been concluded 

 that there is a more solid part arranged like the fibres of a 

 sponge, or like the films of a mass of soap-bubbles, with a more 



i 



