1900.] Symbiosis and Symbiotic Fermentation. 261 



WEEKLY EVENING MEETING, 



Friday, February 9, 1900. 



Alfred B. Kempe, Esq., M.A. F.R.S., Vice-President, 

 in the Chair. 



Professor J. Reynolds Green, Sc.D. F.R.S. 



Symbiosis and Symbiotic Fermentation. 



The features of socialism are realised perhaps more fully in the 

 vegetable world than in any other sphere of life. What we gene- 

 rally call a plant and think of as an individual may with much 

 more appropriateness be considered a colony, composed of units which 

 are essentially similar, which live together in enormous numbers, 

 and which divide up the work of the community among themselves 

 with the greatest completeness; securing thereby to the greatest 

 extent possible the well-being of the colony, so that by this thorough 

 co-operation of all its constituent members it comes to possess so 

 marked an individuality that its composite character escapes our 

 observation. 



With few exceptions every plant is divided up into a number 

 of cavities of varying size and shape, limited by delicate mem- 

 branes of varying thickness and texture. These chambers are the 

 dwelling places of the units of which I have spoken, which may be 

 seen by careful examination to occupy them. The units are known 

 as protoplasts ; each consists of a small piece of living substance 

 possessing a certain degree of structure or differentiation. Each is 

 in communication with its intermediate neighbours by very delicate 

 filaments which extend through the separating walls, so that all the 

 protoplasts of a plant are in actual connection with each other. 

 The shape and disposition of the protoplast within its chamber varies 

 a good deal ; some fill the whole space, others occupy only part of 

 it, and in the majority of cases they line the cell membrane as a 

 colourless transparent film, having a large cavity filled with water 

 in the centre. 



In studying the manner of the growth and development of almost 

 every plant we find this view of its structure so placed before us 

 that we cannot escape the conclusion with which I started. Every 

 plant which is developed sexually begins its career as a single proto- 

 plast without any cell-wall, and from this simple individual the most 

 complex plant-body is gradually constructed by the process of multi- 

 plication of protoplasts. The protoplasts from which various plants 

 start their development are not alike in all cases. In some of the 

 simplest sea-weeds we find them free-swimming bodies, makin« their 



