Bd. XC. No. 3. XXIII. Jahrgang. 



Botanisches Centralblatt. 



Referirendes Organ 



der 



Association Internationale des Botanistes 



für das Gesammtgebiet der Botanik. 



Herausgegeben unter der Leitung 

 des Präsidenten : des Vice-Präsidenten : und des Secretärs : 



Prof. Dr. K. Goebel. Prof. Dr. F. 0. Bower. Dr. J. P. Lotsy. 



von zahlreichen Specialredacteuren in den verschiedenen Ländern. 



Dr. J. P. Lotsy, 



Chefredacteur. 



No. 29. 



Abonnement für das halbe Jahr 14 Mark 



durch alle Buchhandlungen und Postanstalten. 



1902. 



Alle für die Redaction bestimmten Sendungen sind zu richten an Herrn 

 Dr. J. P. LOTSY, Chefredacteur, Leiden (Holland), Oude Rijn 33 a. 



Referate. 



ROBINSON, B. L., Problems and possibilities of syste- 

 matic botany. (Botanical society of America. Publication 

 18. Address as retiring President at the Denver meeting, 

 August 28, 1901.) 



The great and increasing activity in taxonomic work is 

 pointed out, representing rather a vast accumulation of facts 

 than their definite Organization. The writer makes a strong 

 plea for good form in presentation, calling attention to the fact 

 that lucidity of exposition goes far to carry conviction. Insuf- 

 ficient characterization of species is noted; but special criticism 

 is leveled against the recent tendency to voluminous descriptions 

 that contain the essential and the trivial jumbled together, with 

 no clear statement of the differential characters. Carelessness 

 as to the citation of the type is also spoken of and illustrated. 

 In reference to the subject-matter of taxonomic botany, rather 

 than the form of presentation, the writer first discusses the 

 artificiality that lingers in our so-called natural System. Much 

 of this arises from the conception of species, many of those 

 published being „but chance combinations of inconstant cha- 

 racters", and not to be put in the same category as those of 

 clear definition. Species as now recognized are not equivalent 

 things, but represent a hodgepodge of non-equivalent forms. 

 Species must be subjected to a gradual reclassification along 

 more definite lines. With this end in view, the subjects that 



Botan. Centralbl. Bd. XC. 1902. 4 



