Munson, Organization and Polarity of Protoplasm. 385 



IV. 

 Theoretical Suggestions. 



It seems evident that, in dealing with protoplasm, we are 

 not studying matter in its elementary form. When we speak of 

 the functions of the cell, we assume that it is an organism. The 

 history of an individual cell, like that of the sperm cell of Papilio 

 rutulus, forces upon as the conviction that it is an organism, 

 which by a long evolutionary process, has acquired an autonomy 

 sufficient for its own needs. The ectosarc of Amoeba, the chorion 

 of eggs, are, in part, secretion products, which tend to isolate the 

 living protoplasm from other bodies; and to give a definite limit 

 to the area within which a balance between waste and repair is 

 maintained. There results a restricted area in which a delicate 

 balance between analytic and synthetic chemical processes is 

 maintained, and in which the transformation of physical forces 

 is nicely adjusted. Antibodies, antitoxins and ferments, which 

 many, if not all cells, produce, are also well adapted to preserve 

 the autonomy of the cell. In watching the growth of the ovarian 

 egg, which may extend through many years, one cannot fail to 

 observe how food material, metaplasm, and yolk accumulate, 

 aided by the secreting follicle, and epithelial cells. Much more 

 of this is elaborated than is needed for the immediate use of the 

 cell. It is probably the same with other needed chemicals and 

 oxygen. That this gives the cell a certain independence or staying 

 power, so to speak, is evident every where; but especially so in 

 the egg of Limulus, which is able to maintain its vitality under 

 the most adverse conditions, for many months, without food and 

 without even the usual supply of salt water. 



While we attempt to explain vital phenomena by the various 

 tropisms, the fact seems to be that protoplasm, as it develops, 

 becomes more and more seif determined, more and more indepen- 

 dent of external influences ; and indeed resists those changes which 

 external influences normally produce in lifeless matter. The cell 

 seems to possess the power to regulate its responses to external 

 influences by a process of inhibition. There is a disproportion 

 between the Stimulus applied and the results which follow. This 

 distinguishes living protoplasm from ordinary chemical substances. 

 Hence the difficulties always experienced in attempting to explain 

 life in terms of chemistry and physics. 



What is there in living protoplasm which is responsible for 

 this resistance to physical and chemical influences? I take it 

 to be the structure which has been gradually developed through 

 a long process of natural selection, by trial and failure. The 

 various elements of the protoplasm have finally become so ad- 

 justed to one another as to supply, for a while at least, each others 



VIII. Internationaler Zoologen- Kongreß. 25 



