II INTRODUCTION. 



of the vagcular cryptogamg are arranged afber that of Engler and Pra.ntl. 

 Of the sp3cios and varietie^ mentioned in this volume, foi*ty-five are proposed 

 as new sp3cies and one is regarded as a new variety of a known species. 

 One new genus, Diplocarex, has been proposed, and one family, Connaracese, 

 and twelve genera are mentioned as new to the flora of Formosa. The latter 

 genera are as foUows : — Ronrea, Gaucalis, Sium, Conioselinurn, Boerlagio- 

 dendron, Amitodigma, Phyllomplvax, Eri/throdes, Thrixspermum, Ascocerdrum, 

 Ilolcoglossum, Trichoglottis. Thus, up to the present date, the flora of Formosa 

 represent3, so far as is known, 3,658 spscies iind 79 varieties, belonging to 

 1,197 genera and 170 families. 



The original plan of the work, as above stated, was that it should be 

 completed in fiffceen vohimes, and I still intend, if circumstances permit, to 

 publish five more vohimeS, issuing one each year. The completion of the 

 study of the flora of Formosa, which is the real aim of this work, is some- 

 thing one cannot expecfc to a€CompKsh even in a much longer time. For the 

 present one can only hope that nothing will happen to interfere with the 

 completion of the work as originally planned. For this all things seem to 

 promise well. On the other hand there is always the possibility of a change 

 in one's personal circumstances, and it would be unfortunate if this work in 

 which I have been engaged for a score of years should for any reason come 

 to an abrupt end and be left without having been given even a tentative form 

 of completion. Such considerations have led me to think that I should avail 

 myself of the opporfcunity presented by the pubKcation of Volume X. to give 

 to it something of the formal character of a concluding number of the series. I 

 should then be quite satisfied to think that the work had been formally completed, 

 even should the continuation of the latter part unfortunately be interrupfced. 



Accordingly, Volume X. contains a general index to the series, from the 

 first volume to the tenth, and also to the studies which I pubHshed while I 

 was preparing this work on Icones. I have also added two papars, namely : — 

 " An interprekition of Goethe's BlaU in his * Metamorphose der Pflanzen ', 

 as an Explanation of the Prindple of Natural Classification " and *' The Natural 

 Classification of Plants, according to the Dynamic S^-stem". The latter deals 

 especially with the natural system estabHshed uj)on the principle on which, 

 since my return from Tonkin in 1917, I have been reflecting, and refers 

 generally to the explanation of natural classification to which my attention was 



