420 VEGETABLE PHYSIOLOGY 
CHAPTER XXV 
REPRODUCTION 
The phenomena we have hitherto been considering all 
concern the life of the individual plant. As this, however, 
at the best is comparatively limited in duration, we find plants 
possessed of the power of giving rise to new individuals. The 
process of originating each new individual from its parent 
or parents is known as reproduction. 
We have seen that the life of the plant is essentially 
bound up with the individuality of the protoplasts which 
compose it. Many plants consist of but a single one of 
these organisms ; others are composed of many, some of a 
very large number. We have seen reason to look upon 
each of these aggregations of protoplasts as a large colony 
whose members have become differentiated in various 
ways to carry out to the greatest advantage the vital pro- 
cesses of all. In the simplest forms, such as filaments of 
protoplasts like Spirogyra or Ulothrix, each protoplast is 
apparently independent in its behaviour, though mechani- 
cally attached to its neighbours. In more complex and 
bulky forms this independence has been given up in favour 
of complete co-operation for the general welfare. 
As every plant, then, is composed of either one proto- 
plast or many, we may in the latter case distinguish 
between the colony and its constituents. The term in- 
dividual is usually associated with the former, and we speak 
of reproduction as leading to the appearance of such in- 
dividuals without making any reference to the protoplasts 
