194 SECTIONAL ADDRESSES. 



our Herbaria and described, and our knowledge of tbe geographical range 

 of species and the composition of the genera has been greatly extended. 

 But this, it now appears, is only the beginning of the enterprise, as may 

 be gathered from a study of the developments that are taking place with 

 regard to the floras of those countries or regions which are capable of 

 being subjected to a more intensive type of survey. 



In the case of any region or country, the first thing to be done is to 

 assemble the material, to put it in order and assign names to the ' species, ' 

 that is, the definitely distinct assemblages of very closely related plants ; 

 but we are realising now, I think, that such work is rather of a preliminary 

 and tentative nature, and cannot be regarded as in any way final. It is 

 only when we are able to make an intensive study of the vegetation of a 

 given area, and undertake a critical examination of a wide range of 

 specimens, which appear to fall within the bounds of what may have been 

 described as a ' species,' that we can feel justified either in accepting the 

 original definition and description or, on the other hand, in forming an 

 entirely new conception, which may result in the original ' species ' being 

 regarded as a ' habitat form,' a ' variety ' or a ' genotype ' or a member 

 of a compound species. 



Taxonomic workers, more especially in the past, have tended to fall 

 into one of two categories, for to some a ' species ' has covered a wide range 

 of forms grouped around a mean type, while others have taken a more 

 restricted view and their species have represented far smaller and more 

 sharply defined classificatory units. Both methods have been of value ; 

 the broader view has had its advantage very often in relation to questions 

 of geographical distribution, while the narrower one has caused us to 

 inquire into questions relating to the origin of species themselves and the 

 significance of so-called ' varieties.' They have also had their drawbacks, 

 since in the one case many matters relating to the influence of habitat, 

 general conditions, &c., have not been fully appreciated, while in the other 

 the possibilities of hybridisation, segregation and adaptation have usually 

 received little or no recognition. 



The intensive study of the flora of a region, or of particular genera, 

 such, for instance, as Rubus, Taraxacum or Hieracium, has led in some 

 cases, I feel, to the adoption of a very narrow, or I might call it a 

 ' parochial,' outlook, which has tended to detract from the importance of 

 Taxonomic work in the eyes of the younger botanists entering on the paths 

 of a botanical career from our universities. To them, and to many others, 

 the sole aim and occupation of the ' local ' systematist has seemed to be 

 to browse along a hedgerow in order to find a somewhat dubious ' new 

 species,' and then with no small pride to prepare and publish its descrip- 

 tion. In the past, in somewhat petty work of this character, no attempt 

 was made to study effects of light and shade or other environmental 

 conditions, or to make cultural experiments to test the validity or otherwise 

 of the find. I believe it is now properly recognised that such short cuts 

 to transitory glory are a hindrance rather than a help to the progress of 

 Systematic Botany, and that the many problems which arise when a flora 

 comes to be studied critically and intensively, can only be solved by means 

 of experiment. Such experiments may involve controlled cultivation, 

 genetical research and very careful tabulation of statistics before full light 



