K,— BOTANY. 243 



has long ago designated these as ' phylloides,' while his ' cauloides ' 

 correspond to the leaves of ferns. I do not propose here to discuss this 

 difficult question. The present purpose is fully served by showing that 

 induction from the facts of land-living plants alone will now give a 

 reasonable history of the origin of leaves of the Filicinean type, without 

 any need to refer to some transmigrant Alga to explain it. Why should 

 we assume any limit to the capacity of Organic Nature to originate new 

 members 1 Or to do this in more than one way, and in more than one 

 phyletic line ? At the back of the theory of Transmigration is the 

 assumption that she cannot, or probably would not, do this. But a wide 

 comparison of things now living before our eyes, or that have lived, 

 shows that she can, and that she has done it repeatedly. 



Palseobotanical discovery has been greatly advanced within the 

 period under review. The features of the vegetation of Mesozoic time are 

 becoming clearer than ever before under the hands of Professor Seward. 

 The Carboniferous Flora has been richly presented to us by Williamson, 

 Scott, Oliver, and Kidston in Britain, and by Continental workers such as 

 Eenault, Zeiller, Bertrand, Nathorst, and Solms-Laubach. We are now 

 able to substitute something positive in place of vague surmisings. Not 

 only do the new facts illuminate our knowledge of plants now living, but 

 they also apply a check upon theories as to their origin. Latterly a vision is 

 becoming ever more and more real of a Devonian flora, revealed by 

 Kidston and Lang at home, and by other workers in Scandinavia, in 

 Germany, and in America. Given more extended collecting, an improving 

 technique, and the fortune of finding more material as well preserved as 

 that at Rhynie, who knows biit what the coming decades may see the land 

 of the Devonian period clothed before our eyes by a flora no less stimulating 

 and even more suggestive than that of the coal 1 But though Devonian 

 lands are the earliest yet known to have supported a sub-aerial flora, the 

 highly advanced structure of such a fossil as Palccopitys Milleri suggests 

 that we are still far from visualising the actual beginnings of Land 

 Vegetation. Moreover, the mixture in the Rhynie Chert of Algal types 

 with vascular land-plants presents at the moment a problem as perplexing 

 as it is ecologically strange. It is always difficult to estimate justly the 

 times in which we live ; but we may well believe that the future historian 

 of botany will note the present period as one specially marked by 

 successful study of the floras of past ages, and by the increasing cogency 

 of their comparison with the vegetation of the present day. 



The ' Annals of Botany ' as an Historical Document. 



Perhaps too much of your time has been claimed for morphological 

 questions, which are closely related to the dates of the three meetings 

 of the Association here in Oxford. The brief space that remains may be 

 devoted to a more general survey of the period which these dates cover. 

 In this we could not do better than to take as an index the pages of the 

 'Annals of Botany,' for the existence of which we owe a deep debt to the 

 Oxford Press. In 1860 there was no organised laboratory teaching of 

 Botany in any University in Britain ; and as yet there was no journal of 

 the nature of the ' Annals.' But the revival of close observational study in 

 Botany under Huxley and Thiselton Dyer at South Kensington in the early 



