74 MORPHOLOGICAL DEVELOPMENT. 



Hence, then, we are not without an interpretation of those 

 over- developments which the phamogamic axis occasionally 

 undergoes. Fig. 104, represents the phcenogamic bud in its 

 rudimentary state. The lateral process b, which ordinarily 

 becomes a foliar appendage, differs very little from the 

 terminal process c, which is to become an axis — differs 

 mainly in having, at this period when its form is being 

 determined, a smaller bulk. If while thus undifferentiated, 

 its nutrition remains inferior to that of the terminal process, 

 it becomes moulded into a part that is subordinate to the 

 general axis. But if, as sometimes happens, there is supplied 

 to it such an abundance of the materials needful for growth, 

 that it becomes as large as the terminal process ; then we 

 may naturally expect it to begin moulding itself round an 

 axis of its own : a foliar organ will be replaced by an axial 

 organ. And this result will be especially liable to occur, 

 when the growth of the axis has been previously under- 

 going that arrest which leads to the formation of a flower ; 

 that is, when, from defect of materials, the terminal process 

 has almost ceased to increase, and when some concurrence of 

 favourable causes, brings a sudden access of sap, which reaches 

 the lateral processes before it reaches the terminal process. 



§ 198. The general conclusion to which these various lines 

 of evidence converge, is, then, that the shoot of a flowering 

 plant is an aggregate of the third degree of composition. 

 Taking as aggregates of the first order, those small masses 

 of protoplasm which ordinarily assume the forms under 

 which they are known as cells ; and considering as aggregates 

 of the second order, those assemblages of such cells which, 

 in the lower cryptogamia, compose the various kinds of thal- 

 lus ; then that structure, common to the higher cryptogams 

 and to phoenoganis, in which we find a series of such groups 



relatively more subordinate to the forces exerted on them by the larger aggre- 

 gates of molecules that are at greater distances, and thus arc left to arrange- 

 themselves round fewer axes into larger crystals. 



