250 



Scientific Proceedings, Royal Dublin Society. 



from Ginlcgopliyllum now revealed it might be better to call the Kiltorcan 

 plant Kiltorhensia devonica. The illustrations show the rootstock as seen from 

 various aspects. Some of the leaves seen in fig. 4, PL XII, are reduced, and 

 almost scale-like. The specimen (PI. XIII, fig. 1) was found of a revealing 

 nature. There is a well-pronounced stem, from which arises an apical tuft 

 of spirally arranged leaves. Here and there may be seen a lobed, wedge- 

 shaped leaflet. The rachis, to which a leaflet is seen attached, shows several 

 vascular bundles traversing it, reduced to a leaf -trace or two (?), at the point 



Botrychium simplex (restored). 



of insertion. Such a specimen suggests comparison with several groups of 

 plants, and even with the leafy spur of Ginkgo itself. Just as in ontogeny, 

 the many buds are a repetition and multiplication of the plumule of the 

 seedling, so phylogenetically the apex of the Ginkgophylhtm rootstock might 

 find itself multiplied in the shoots of the arboreous Ginkgo. Accepting the 

 view that the leaf is differentiated into two dissimilar portions — one laminated 

 and lobed (Ginkgo-like), the other ribbon-like and forked {Triclwpitys or 

 Biwanopliylhcm-likc) — an interesting question arises. Are both portions 



