I02 The Ohio Naturalist. [Vol. XIII, No. 6, 



the various members cf primitive seed plants in the Carboni- 

 ferous and Devonian, the conclusions drawn from these sources 

 are no more reliable or fundimental than those from living forms, 

 except that they aid in filling up gaps which occur among those 

 surviving to the present time. 



What is needed, of course, is a series of ancestral fossils below 

 the Devonian, leading up step by step through the successive 

 geological formations, from a pteridophyte ancestor to the Devon- 

 ian Cordiates. The speculations of those who reason from fossils 

 of lower order which occur after the higher have appeared are of 

 no more weight than speculations based on the present flora, 

 which is, after all, more reliable than the extremely fragmentary 

 material of the fossil record. It may be stated that there are, at 

 present, no evident data in support of the direct relationship of 

 any gymnospemi classes unless we consider the Bennettilales 

 as a class distinct from the Cycadales. The relationship of these 

 two groups seems to be quite certainly established. But at 

 present most systematists would probably agree that the Cycadales 

 and Bennettilales are closely related orders. 



The strobili or cones of the Coniferse are here regarded as 

 true strobili and not as inflorescences, and Bessey's view that 

 the staminatc and ovulate cones arc strictly homologous is main- 

 tained. When one compares the pine carpel, with its prominent 

 ovuliferous scale, with the dwarf branch, one might easily be 

 tempted to make them homologous; but when one goes a little 

 further and finds the same peculiarities in the carpels of genera 

 like Abies, where no dwarf branches exist, the conclusion has 

 little or no weight. Much of the discussion as to the nature of 

 the carpellate strobilus of the Pinacea2 has been based on the 

 occurrence of occasional abnormal structures, but one can find 

 abnormal cones that argue for the view that the carpellate cones 

 are true strobili and not inflorescences, just as well as one can 

 find structures that would indicate the opposite. For example, 

 Fischer has described an abnormal cone of Pinus laricio, the 

 lower part of which had normal stamens and the outer end of 

 the same axis had carpels of the usual type. This bisporangiate 

 cone was in the position of a staminatc cone beside a normal 

 staminatc cone. The carpels had the usual carpellate bract 

 and ovuliferous scale. I regard the ovuliferous scale as a peculiar 

 structure not homologous to either stem or leaf. The fleshy 

 structures in the Taxales must be of a similar nature. The aril 

 of Taxus, for example, is either homologous or analogous to the 

 ovuliferous scales of Abies and Picca. 



The structure with the two ovules in Ginkgo is regarded as 

 a megasporophyll, the whole cluster at the tip of the dwarf branch 

 being simply a cluster of carj^cls. The same interpretation must 

 then, of course, also be given to the staminatc structures. The 



