94 PLANT MORPHOLOGY 



than the former. This phylogenetic problem, however, is with our 

 present means and knowledge not subject to solution with certainty, 

 while the ontogenetic problem, on the contrary, is. Problems, 

 however, which may not be solved appear to me less important 

 than those which may. 



To be sure, the solution of the ontogenetic problem is hedged 

 about with great difficulties. For the results which have already 

 accrued, valuable as they may be, take their importance from the 

 fact that they lay the foundation for the future work: what changes 

 take place during transformation, and upon what outer and inner 

 conditions are they dependent? We may not comfort ourselves 

 nowadays as at one time Goethe could with the view that flowers 

 differ from the vegetative shoot in a refinement of the sap; rather 

 would we know what change of the materials, and what other 

 changes, are connected with the order of successive developmental 

 stages of the flower. This, to us as good as unacquired knowledge, 

 should give us a more penetrating glance into the nature of develop- 

 ment than we have as yet had. To just this purpose plants are 

 especially well adapted, for experience has shown us that the de- 

 velopment of a plant is not produced as is the melody in a music 

 box, in a definite order, so long as the outer source of power is present 

 to start it; for the experiments of the last few years indicate rather 

 "that the form-relations of chlorophyll-bearing plants are not pre- 

 determined in the germ cell, but in the course of development." 1 As 

 a result we can not only arrest development at any particular stage, 

 but we can also cause fundaments to unfold which were previously 

 "latent." Historical morphology has contented itself as regards 

 the unfolding of latent fundaments also with an historical explana- 

 tion of the facts. The observation, e. g., that instead of the seed 

 scale of the Abictineaz under certain circumstances an axillary 

 shoot appears, has been used by prominent botanists to support the 

 conclusion that the seed scale has arisen phylogenetically from a 

 shoot. Such an hypothesis would get beyond the rank of pure sup- 

 position if a living or fossil form certainly related to the Abietinece 

 could be pointed out, the cones of which bear in the axils of the cover 

 scales shoots possessed of macrosporophylls. As long as such proof 

 is not forthcoming, we stand opposed to a phylogenetic explanation 

 of this observation, " kilhl bis ans Herz hinan." We seek rather to 

 establish the conditions under which the fundaments, which other- 

 wise become seed scales, develop into shoots, and hold before us 

 therewith the possibility that the forbears of the Abietinece could have 

 borne their ovules upon an axillary outgrowth of the cover scales, 

 which, indeed, possessed the ability under certain circumstances 

 which disturbed the normal development to form shoots, but which 

 1 Goebel, Flora, 1895, p. 115. 



