1878.] 



Preside nt?s A ddress . 



55 



Research." Mr. Thiselton Dyer's order of procedure is the reverse 

 of Count Saporta's, and his method entirely different. He first gives 

 a very clear outline of the distribution of the principal existing 

 Floras of the continents and islands of the globe, their composition, 

 and their relations to one another, and to those of previous geological 

 epochs. He then discusses the views of botanists respecting their 

 origin and distinctive characters, and availing himself of such of their 

 hypotheses as he thinks tenable, correlates these with those of 

 palaeontologists, and arrives at the conclusion " That the northern 

 hemisphere has always played the most important part in the evolution 

 and distribution of new vegetable types, or in other words, that a 

 greater number of plants has migrated from north to south than in the 

 reverse direction, and that all the great assemblages of plants which 

 we call Floras, seem to admit of being traced back at some time in 

 their history to the northern hemisphere." This amount of accordance 

 between the results of naturalists working wholly independently, from 

 entirely different stand-points, and employing almost opposite methods, 

 cannot but be considered as very satisfactory. I will conclude by 

 observing that there is a certain analogy between two very salient 

 points which are well brought out by these authors respectively. Count 

 Saporta, looking to the past, makes it appear that the fact of the 

 several Floras which have flourished on the globe being successively 

 both more localised and more specialised, is the natural result of con- 

 ditions to which it is assumed our globe has been successively sub- 

 jected. Mr. Dyer, looking to the present, makes it appear that the 

 several Floras now existing on the globe are, in point of affinity and 

 specialisation, the natural results of the conditions to which they must 

 have been subjected (luring recent geological time on continents and 

 islands with the configuration of those of our globe. 



The modern development of botanical science, being that which 

 occupies my own attention, is naturally that on which I might feel 

 especially inclined to dwell ; and I should so far have the excuse that 

 there is, perhaps, no branch of research with the early progress of 

 which this Society is more intimately connected. 



One of our earliest Secretaries, Robert Hooke, tw r o centuries ago, 

 laboured long and successfully in the improvement of the microscope 

 as an implement of investigation. He was one of the first to reap the 

 harvest of discovery in the new fields of knowledge to which it was 

 the key, and if the results which he attained have rather the air 

 of spoils gathered hither and thither in a treasury, the very fulness 

 of which was embarrassing, we must remember that we date the 

 starting point of modern histology from the account given by Hooke 

 in his " Micrographia " (1667) of the structure of cork, which had 

 attracted his interest from the singularity of its physical properties. 



