BOTANICAL SUBJECTS. 97 



form, or any part of a form, which exists at present, as only a 

 further development or modification of something that has gone 

 before it, loAver down in the series. 



We are only concerned in these pages with the evolution of 

 plants. The question is how to account for all the parts of plants 

 "we see around us, stems, branches, roots, leaves, buds, flowers, 

 fruits, seeds, &c., on the principle of evolution, and all emerging 

 out of the same raw material of unicellular bodies, or out of their 

 near relatives the multicellular bodies found in sea and fresh 

 water, such as seaweeds and others. 



Are all organs of plants new creations, or are they simply 

 derivatives ? They are an unfolding of less complicated material 

 into a more complicated structure, such as the unfolding of a 

 branch and flower out of the cellular material of a bud. 



The theory of evolution must be accepted in its totality, other- 

 wise it is not evolution at all, but some other theory. If we are 

 to bring in the help, at odd intervals, of a Deity, to account for 

 what we do not understand, it would be much simpler to say at 

 once that He, She, or It did it all from beginning to end. 



I do not think that the last word has been said regarding the 

 different organs of plants found in books on structural botany. I 

 do not consider that the origin of the different organs or parts 

 of a plant have received an exhaustive treatment, based on 

 evolutionary lines, so that nothing further can be said about 

 them. 



I think Weismann is right in considering all life as com- 

 mencing in unicellular bodies, having the property of feeding and 

 reproducing themselves. And that, as they aggregated into 

 multicellular bodies, it was to the advantage of the whole colony 

 that a sub-division of labour should evolve ; that some should give 

 their individual attention to the one function, and perfect that, 

 and some retain only the other function, and perfect that. 



The upshot was that, in an aggregation of cells, some became 

 what we call vegetative, as feeders of the whole colony, and other 

 became what we call reproductive cells, that is, nurseries of ne"w 

 colonies. We must not suppose, however, that each set of cells 

 had lost its twin function in perpetuity. Xot at all. The one 

 function of the original cells remained in abeyance, because the 

 other function had a preponderating energy. 



A p. 1724. <j 



