HOTANILAL SUBJECT.-?. 327 



Then we would have cue monopli}toii becoming parasitic on 

 another monophytou.* If both happened to find benefit from 

 the association, their zmion, as a factor in further selection, 

 would be secured, and henceforward the}- would have to settle 

 among themselves what space and part of the composite body 

 each should more l^eneficially occupy, and what the function of 

 each would be in this compound and heterogeneous body. There 

 are many romances in nature, and this, not impos-ibly, may be one 

 of them I 



This hypothesis no doubt is based on slender exidt-nce, but 

 all hypotheses commence by being crude, as e^"ery idea must 

 necessarily pass through its crude stage, whether it be pul)lished 

 in all its crudity, or whether it be kept " in jwfto," till it is 

 matured. 



We must conceive a transition from the cellular to the vascular 

 stage of plant life, and on principles of evolution there appears 

 to me only two hypotheses possible to account for the transition 

 of the one to the other. One is that already given ; the other 

 is this : 



Dr. Dallinfrer has shown that even among monads there is 

 variation, and consequent natural selection. Indeed, this variation 

 appears to be a universal law of matter, Avhether animate or 

 inanimate. But just now we have only to deal with living things, 

 in their very simplest forms. 



This being so, it would follow that the same unicellular bodies, 

 after aggregation into multicellular groups, would be liable to 

 variation, and it is conceivable that some would so vary as to 

 become spiral, and take their place in the building up of the 

 vascular system of the colony. The supposition is that the cells 

 would continue to vary after grouping into colonies, and that in 

 time the different variations would occupy the places most 

 l>eneficial to the life of the colony as a ichole. Naturally, those 

 colonies whose individual cell-variations could not understan^l 

 each other, so to speak, would die away in the course of 

 competition with other colonies, for want of that exquisite 



* When I s;ay parasitic, I mean that the germ of one monad found 

 entrance into another, and associated itself with it. 



