lii PROCEEDrXGS OF THE 



less confirmed from other sources ; but an accidental oversight on 

 the part of a naturalist of established reputation is the most difficult 

 to remedy, notwithstanding the eagerness with which some begin- 

 ners devote themselves to hunting them out. No botanist was, I 

 beKeve, ever more careful in verifying his observations over and 

 over again, and in submitting them to the tests supplied by the ex- 

 traordinary methodizing powers of his mind, than Hobert Brown ; no 

 one has ever committed fewer of what we call blunders, or esta- 

 blished his systematic theories on safer ground ; yet even he has been 

 detected in a few minor oversights, eagerly seized upon by a set of 

 modem speculative botanists, lovers of paradoxes, as justifying them 

 in devoting their time and energies to the disputal of several of his 

 more important discoveries and conclusions. 



The value of a description as to fulness and conciseness is prac- 

 tical only, but in that point of view important. A description, how- 

 ever accurate, is absolutely useless if the essential points are omitted, 

 and very nearly so if those essential points are drowned in a sea of 

 useless details. The difficulty is to ascertain what are the essential 

 points, — and hence one of the causes of the superiority of Mono- 

 graphs and Floras over isolated descriptions, such as those of Zoolo- 

 gies and Botanies of Exploring Expeditions, which I insisted on in 

 my Address in 1862 : in the former the author must equally examine 

 and classify all the allied races, and thus ascertain the essential 

 points ; in the latter case he is too easily led to trust to what he be- 

 lieves to be essential. My own long experience in the using as well 

 as in the making of botanical descriptions has proved to me how 

 difficult it is to prepare a really good one, how impossible to do it 

 satisfactorily from a first observation of a single specimen. How- 

 ever carefuUy you may have noted every point that occurs to you, 

 you will find that after having comparatively examined other speci- 

 mens and allied forms you will have many an error to correct, many 

 a blank to fill up, and much to eliminate. I have had more than 

 once to verify the same species in two authors, the one giving you a 

 character of a few lines which satisfies you at once, the other obli- 

 ging you to labour through two or three quarto pages of minute de- 

 tails from which, after aU, some of the essential points are omitted. 



But the great problem to be solved at every stage in systematic 

 or descriptive biology, and that which gives it so high a scientific 

 importance, is the due detection and appreciation of affinities and 

 mutual relations ; and in this respect the science has made immense 

 progress within my own recollection, and especially diuing the last 

 few years. The gradual supplanting of artificial by natural classi- 



