— 279 



it for granted that this statement is all right, we have here a plant 

 that at least with some right may be called an original specimen. 

 I have had an opportunity of examining this specimen, which 

 turned out to belong just to the Neckar -plant. It had O-endo- 

 dermis and was without bundles in the bark. This tells in favour 

 of keeping the name P. fluitans Roth for the Neckar -pi ant. 



This view is strengthened by the examination of three speci- 

 mens of P. fluitans in the Petersburg herbarium and examined 

 by me. On one of these specimens the original label sounds as 

 follows : 



Herb. Schräder 

 P. fluitans R. 



e Palatinatu 

 m. Dr. Roth. 



The second specimen has two labels viz., 



Herb. Schräder 

 Potamogeton fluitans R. 



var. & fol. ellipt. -oblong. 



and : 



Herb. Schräder. 

 Potamogeton fluitans 

 Roth. Flor. Germ, 

 m. Roth. 



The third specimen also has two labels the one of them with 

 the inscription: 



P. fluitans 

 fructu non viso species recognoscenda. 



The four dots indicate a name that I could not surely decipher 

 but it was most likely the name of „Roth". For such an inter- 

 pretation speak the writings on the other label : 



Potamogeton fluitans R. 

 ab ipse Roth, 

 haud frequens apud nos. 



These three specimens of P. fluitans with the designa- 

 tions: „m. Dr. Roth", „m. Roth" and „ab ipse Roth" 

 may well be original specimens even if we are rather 

 critical in the question of priority. Moreover, the anatomical 

 examination just proved that all the three individuals belong to the 

 Neckar -plant; consequently I think we are right in claiming 

 the name of P. fluitans Roth kept for the Neckar- pi ant. 



