50 THE EVOLUTION OF CONTINUITY 



for hostility or unsuitability denotes a quality directly in 

 terms of Repulsion, the force acting for discontinuity, while 

 its opposite, friendliness or suitability, is in terms of Attraction 

 the force acting for continuity. In other words, an act of 

 attraction is an indication of suitable environment and one 

 of repulsion the reverse, and this is true whether the entities 

 attracted or repelled are atoms, molecules, cells, or multi- 

 cellular organisms. Thus, in the case of cells, it is clear 

 that the act of cell-division reflects the institution of hostile 

 immediate environment ; the prospective division-results 

 become mutually repulsive and separate because each is 

 to the other a hostile environment. 



Unsuitable environment may be the result of an 

 organism's own activities, and when this is the case the 

 environment is always a limited one. For example, the 

 malarial amoeba's proper environment is the red corpuscle 

 substance, but this happens to be limited in amount and is 

 finally used up by the enlarging amceba. The corpuscle 

 not only contains no more food for the amceba but has instead 

 the toxic by-products of the organism's metabolism, and the 

 result is that the amceba breaks up into spores and these 

 separate from each other and escape to enter fresh corpuscles. 



The limitation of the malarial amoeba's environment is 

 absolute ; the corpuscle is of a definite small size and is 

 bounded by a containing membrane ; but even where an 

 organism's environment is not thus limited in size to begin 

 with, it may virtually become so by reason of the accumula- 

 tion and non-removal of noxious waste-products. In such 

 cases the organism will occupy a medium of more or less solid 

 consistency. Possibly this may be the reason why the 

 continuity of the threads or " hyphse " of a simple fungus 

 mycelium is interrupted periodically by spore-formation. 

 Certainly increasing environmental hostility must be a 

 factor in producing the discontinuity of the spore, for when 

 the spore enters a suitable environment growth in continuity 

 is once more manifested. 



Hostile environment in the form of all external forces 

 working for the production and maintenance of discontinuity 

 will always be encountered by living organisms. 



Now the act of gamete-conjugation with which the growth. 



