The Individual Plant 



within have been radically altered. They are suddenly 

 called upon to respond to a very unlikely emergency, and 

 they rise or rather expand and divide to the occasion. 



Amongst the many triumphs in fossil botany, there 

 is the discovery from microscopic sections of fossil 

 Brachyphyllum stems, that this plant also healed its 

 virounds in the Jurassic Age by means of resin secretions,^ 



Dr. Nemec's important work on Regeneration ^ (pub- 

 lished in 1905, 360 pp.) has called attention to another 

 series of facts of a strange and interesting character, 

 and which reveal the same readiness of vegetable cells 

 to undertake any work required of them. 



One would think that the beheading of the growing 

 point of a stem or root would be an irreparable damage. 

 But that is by no means the case ! A decapitated root 

 at once begins to form a new root tip. The living cells 

 behind the cut surface form a temporary or provisional 

 root cap, and then an arched or dome-like mass of young 

 growing cells on which a new growing point is formed. 



Not only so, but if the root tip is only half cut across, 

 the cells behind it at once begin to form a new growing 

 point, and the old injured one is ruthlessly sacrificed, 

 being separated off by a layer of easily detached cells.® 



This reminds one of those worms which when de- 

 capitated can form a new head. 



In the case of some ferns (Adiantum sp.), the leaf- 

 growing point may be directly changed into a stem, or 

 runner growing-point.^ But what is perhaps still more 

 remarkable is the manner in which cut off leaves may 

 take root and produce a whole plant with roots, stems, 

 leaves, and flowers.^^ In the case of Torenia, if a leaf is 

 cut off and laid on moist earth, buds appear all along 

 the leaf and indeed almost anywhere. 



These buds at once begin to grow, each forming a 

 stem and small leaves (the growing tissue is the epi- 



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