TRANSACTIONS OF SECTION D. 679 



Section D.— BIOLOGY. 

 Peesident of the Section.— WILLIAM CARRUTHERS, Pres.L.S., F.R.S., F.G.S. 



THURSBA Y, SEPTEMBER 2. 

 The President delivered the following Address : — 



In detaining you a few minutes from the proper work of the Section, I propose to 

 ask your attention to what is known of the past history of the species of plants which 

 still forma portion of the existing flora. The relation of our existing vegetation 

 to preceding floras is beyond the scope of our present inquiry : it has been fre- 

 quently made the subject of exposition, but to handle it requires a more lively 

 imagination than T can lay claim to, or, perhaps, than it is desirable to employ in 

 any strictly scientific investigation. 



The literature of science is of little, if any, value in tracing the history of 

 species, and in determining the modification or the persistency of characters which 

 may be essential or accidental to them. If help could be obtained from this quarter, 

 botanical inquiry would be specially favoured, for the literature of botany is earlier 

 and its terms have all along been more exact than in any of her sister sciences. 

 But even the latest descriptions, incorporating as they do the most advanced 

 observations of science, and expressed in the most exact terminology, fail to supply 

 the data on which a minute comparison of plants can be instituted. Any attempt 

 to compare the descriptions of Linnaeus and the earlier systematists who, under 

 his influence, introduced greater precision into their language, with the standard 

 authors of our own day, would be of no value. The short, vague, and insufficient 

 descriptions of the still earlier botanists cannot even be taken into consideration. 



Greater precision might be expected from the illustrations that have been in 

 use in botanical literature from the earliest times; but these really supply no 

 better help in the minute study of species than the descriptions which they are 

 intended to aid. The earliest illustrations are extremely rude : many of them are 

 misplaced ; some are made to do duty for several species, and not a few are piu-ely 

 fictitious. The careful and minutely exact illustrations which are to be found iu 

 many modern systematic works are too recent to supply materials for detecting 

 any changes that may have taken place in the elements of a flora. 



But the means of comparison which we look for in vain in the published litera- 

 ture of science may be found in the collections of dried plants which botanists 

 have formed for several generations. The local herbaria of our own day represent 

 not only the different species found in a country, but the various forms which 

 occur, together with their distribution . They must supply the most certam materials 

 for the minute comparison at any future epoch of the then existing vegetation with 

 that of our own day. 



The preservation of dried plants as a help in the study of systematic botany 

 was first employed in the middle of the sixteenth century. The earliest herbarium 

 of which we have any record is that of John Falconer, an Englishman who 

 travelled in Italy between 1540 and 1547, and who brought with him to England 

 a collection of dried plants fastened in a book. This was seen by William Turner, 



