G. M. Wieland — Accelerated Cone Growth in Pinus. 103 



Also, similarly to both ovulate and staminate cone-bearing 

 axes, as well as to occasional single ovulate cones, the main or 

 vegetative axis was prolonged ; although, having been broken 

 away, this feature does not appear in the figure. The present 

 very unusual or even unique group of cones has therefore 

 been produced in the simplest possible manner, namely, by 

 increase in number and crowding to the extent of about a 

 dozen of the ordinary ovulate clusters. 



Moreover, it is from its very simplicity of origin that this 

 fine example of accelerated proliferation appears to me to 

 derive an instructive interest ; for of late there have been 

 accumulating various significant facts pointing toward a deriva- 

 tion of all existing spermaphytes from primitive ferns by way 

 of pteridospermous types. Indeed, it now appears quite prob- 

 able that the production of ferns may well have been Nature's 

 fundamentally greatest achievement in vegetal evolution, and 

 that following this great step, perhaps thoroughly accomplished 

 in Silurian time, advance in reproductive structures was largely 

 along lines of lesser resistance rather than by sheer forward 

 movement. That is, broadly as well as theoretically speaking, 

 the hiatus between monoecious fern prothalli and the seeds of 

 pteridosperms and finally of gymnosperms and angiosperms ; 

 or, more definitely still, the hiatus between asexual fertile fern 

 fronds, and the microsporophyll and carpellary leaf, the stamen 

 and carpel, as seen in their thousand-and-one combinations in 

 strobili flowers and inflorescences, was bridged not so much by 

 the outright evolution of new organs as by more roundabout 

 methods. Such, for instance, are, following the development 

 of either generalized types or organs, extreme reductions, the 

 secondary requisition of organs not originally evolved for the 

 specific purpose or use finally assumed, and especially re- 

 arrangements or regroupings of fertile axes with sporophyll 

 changes sequent to accelerated branching. 



Now, if such conceptions of the descent of the higher types 

 of existing plants from the ferns can in any sense approximate 

 the truth, then the question as to the extent to which sporo- 

 pbyll reduction entered into the evolution of primitive types 

 of cones from a main terminal strobilus like that of Cycas at 

 once arises. And directly corollary to this inquiry there imme- 

 diately comes up for discussion the further possibility of 

 accelerated branching with marked increase in number of par- 

 tially reduced fertile axes. Such, whenever assuming a more 

 or less compacted order constituting in reality primitive types 

 of inflorescences, would, if once coming to appear habitually, 

 readily undergo still other subsequent mutations of form. For 

 example, how else than by some such course of evolution as 

 that here briefly suggested, has the male cone (inflorescence) 



