536 
PHYTOGRAPUY. 
BOOK IV. 
always judge for himself; or, if that should not be in his 
power, he should take care to show which have been ascer- 
tained by himself, and for which he trusts to others. It is 
especially important never to suppose that plants are the same 
whose names are the same. Upon this point it particularly 
behoves the botanist to be vigilant ; for nothing is more com- 
mon than for writers to mistake the plants intended by each 
other. Thus, R. pimpinellifolia of Linnaeus, is R. spinosis- 
sima ; R. pimpinellifolia of Pallas is a distinct variety, if not 
species, called altaica by Willdenow; R. pimpinellifolia of 
Villars is Rosa alpina ; R. pimpinellifolia of Bieberstein is 
probably R. grandiflora. Care must also be taken not to 
suppose that the plants with different names are different spe- 
cies. It frequently happens that a known species, already 
described by one Botanist, is described as new by another. 
This arises from a variety of causes : the original description 
is imperfect or inaccurate, so that the species to which it 
refers cannot be recognised ; or a species may have been de- 
scribed by one Botanist, in a work unknown to another, who 
has therefore described it anew. This is an evil for which 
there is no other remedy than vigilance on the part of those 
who take the lead in science ; ' and who, from time to time, 
apply themselves to purify it from the errors that are daily 
accumulating. So difficult, however, is it to detect repetitions, 
that, even in the publications of the most distinguished and 
skilful writers, they occur in numberless instances : for in- 
stance, the Unonas uncinata, hamata, and esculenta of Dunal 
and De Candolle are identically the same. 
