Botanical Society of Edinburgh. 483 



candid and inquiring botanist should be informed as to the principles 

 I have kept in view. 



" In the first place then, I have desired to make no innovation 

 but what seemed imperatively required for correct elucidation, and 

 have therefore made every effort to profit by the labours of preceding 

 eminent botanists who have particularly studied the Rubi, as Sir J. 

 E. Smith, Drs. Weihe and Nees von Esenbeck, Mr. Borrer and Pro- 

 fessor Lindley. 



" But, secondly, I have observed with the eye of an original ex- 

 plorer, tracing every form that appeared to me different, without re- 

 ference to the ideas of other botanists. And thirdly, having observed 

 the same plants in a living state for several successive years, I have 

 collated and revised my original observations, sketched every appa- 

 rent species, and compared them again and again with the figures, 

 descriptions and named specimens of botanists of authority. Thus I 

 have been enabled in a great degree to understand the forms to which 

 particular names have been assigned, and to test their propriety by 

 my own experience. I trust therefore that I shall not be considered 

 guilty of assumption where I may differ from others, being only 

 anxious for the nearest approximation to correctness. 



" It is unnecessary for me to go into the question as to what con- 

 stitutes a species in this genus ; for, as I have before hinted, it is not 

 unhkely that the forms in every group may be really only varieties, 

 sporting from a normal form and into each other. But if botany be 

 a science of discrimination, it is at any rate convenient to name every 

 remarkable continuing form as a species or subspecies, since other- 

 wise minor variations can scarcely be distinguished, or must be placed 

 in the same rank with more important deviations of structure. In- 

 deed Nees von Esenbeck, one of the authors of the elaborate ' Rubi 

 Germanici,' has well remarked in a letter to the Rev. Mr. Leighton 

 in the ' Shropshire Flora,' — ' I am not of opinion that all the forms 

 proposed by my friend Dr. Weihe as species are to be considered as 

 such, but in my opinion it is absolutely necessary to look for the 

 greatest number of forms which present themselves in the genus be- 

 fore attempting to judge of species and fixing their limits. I can 

 scarcely tell which is most perplexing in the path of our science : 

 whether, with Dr. Weihe, to distinguish as species every form of 

 bramble that presents itself to our view; or, with M. Koch, to consider 

 all as modifications of one only. In this case I do not doubt that these 

 are matters purely of observation, and that the faithful observer of 

 nature will find that the truth really is between these two extremes.' " 



BOTANICAL SOCIETY OF EDINBURGH. 



Thursday, the 11th of April 1844, Prof. Graham, President, in the 

 Chair. 



Various donations to the Library and Museum were announced 

 and the following papers read ; but as all of them will appear in these 

 ' Annals,' their titles only are now recorded. 



1. " On four genera of Desmidiece, viz. Euastrum, Tetmemorus, Mi- 

 crasterias, and Berkleya," by Mr. Ralfs. 



