206 PLANT LIFE 



growth of individual cells, and hence the 

 shape of the colony as a whole. Doubtless 

 the elongated, narrow cylindrical form of 

 fungal hyphae is to be interpreted, in part 

 at any rate, as an expression of this fact. 

 Vegetative reproduction tends, in such forms, 

 to occur by the transverse fission of the 

 cylindrical growths ; but, as we have already 

 seen, multiplicative processes are not identical 

 with those of growth, and both in the fungi 

 and in other lowly plants, nutrition sets other 

 processes in action which lead to the formation 

 of various sorts of specialised reproductive 

 cells. This does not, however, interfere with 

 the ordinary multiplication by fission, which 

 still remains as a common feature among them. 

 In the evolution of the more complex 

 plants, the cells the primitive individuals 

 become organised into a higher individuality. 

 The sense in which we use the term repro- 

 duction gradually and insensibly changes, 

 and we distinguish between cellular multipli- 

 cation and the reproduction of the multicellular 

 individual. We may still think of the multi- 

 plication of cells as reproduction in the 

 abstract, but our unit organism, so to speak, 

 has become transformed; it is no longer 

 identical with the isolated cell, but is repre- 

 sented by the cell colony. Reproduction in 

 such a colony, concretely considered, comes 

 then to signify the process by which, not new 

 cells only, but new colonies are started. It is 

 a change in the point of view. 



