,8^ BOTANICAL NOMENCLATURE. 621 



Ascherson, and Urban, is due the credit of initiating a practical 

 measure which, if adopted, will put a stop to future divagations, and, 

 it may be, neutralise the mischief already wrought. They have sent 

 out to the botanists of the world a memorandum which has already 

 received the adhesion of a very large number, and which is likely, if 

 adopted, to be productive of good results. The document is as 

 follows : — 



Since the time of Linnaeus, botanists have continually en- 

 deavoured to gain a uniform nomenclature, and these endeavours 

 were completely justified on account of an easier mutual under- 

 standing. We know very well that certain differences will always 

 remain, because the decision on some questions only depends on 

 the author's subjective opinion. But we hope that a gradual 

 and continual ■ reformation will bring an essential improvement. 

 O. Kuntze's Revisio Generum has raised an evidenc perturbation, 

 and will cause a complete confusion ; therefore we thought it 

 necessary to propose the following four resolutions, which ri fer only 

 to the genera : — 



I. The starting-point of the priority of the genera as well as 

 the species is the year 1752, resp. 1753. 



II. Nomina nuda and seminuda are to be rejected. Pictures 

 alone, without diagnoses, do not claim any priority of a 

 genus. 



III. Similar names are to be conserved, if they differ by ever 



so little in the last syllable ; if they only differ in the 

 mode of spelling, the newer one must fall. 



IV. The names of the following larger or universally known 



genera are to be conserved, though after the strictest rules 

 of priority they must be rejected ; in many of them the 

 change of the names now used is by no means sufficiently 

 proved. [This list I do not think it necessary to reprint 

 here; it is likely to receive many additions.] 



Ad. I. After Alph. De CandoUe had proposed to take the year 

 1737 as the starting-point of the priority of genera many botanists 

 had acknowledged it. But we think that the turning-point from the 

 ancient botany to our modern science rests in the introduction of the 

 binomial nomenclature. Therefore we propose, after a previous 

 communication with Alph. De Candolle, to remove the starting-point 

 for both, the species as well as the genera, as far as to the year 1753, 

 resp. 1752, date of the St'ecies Plantanim, ed. i (1753), with the 4th ed. 

 of theGenera Plantavnm (1752). Before that time the scientific position 

 of Linnaeus is not superior to Tournefort, Rivinus, and many other 

 botanists, who often had described and segregated the genera more 

 exactly than he did. 



Ad. II. Many genera have been founded on a picture only, without 

 a diagnosis. No doubt, by means of it a species sometimes can 

 clearly be made out and recognised, and if the picture is a good one, 

 all the characteristics of the plant can be observed. But a picture 

 can never show the special characteristics alone, which raise the 

 genus above the other of its affinity. A genus only gains priority by 

 a verbal diagnosis, and nomina nuda and scmimtda aie to be rejected ; 



