xx INTRODUCTION. 
to it, I have taken it as the basis of my own. It is 
true that the additions and alterations I have found it 
necessary to make, have been considerable, but they 
are such as Mr. Woods himself would probably have 
resorted to, had exotic specimens entered into his plan. 
His divisions however are confessedly made without 
reference to any but British Roses, and so far his ar- 
rangement is defective. In 1816, a year after Mr. 
Woods’s paper was read before the Linnean society, 
Dr. Ambrosio Rau published his “ Enumeration of the 
Roses growing about Wurtzburg,” arranged according 
to anew method. The remarks attached to the species 
are useful and accurate, but the manner in which they 
are disposed is defective. It however deserves atten- 
tion for the care which the subject has evidently re- 
ceived from the author. These two are the only at- 
tempts to form a new arrangement of Roses which it 
is necessary to notice. In both, the species are too 
much multiplied, and consequently their characters are 
sometimes unsatisfactory. 
In the following disposition one of my principal ob- 
jects has been to make it natural. To effect this it was 
necessary to become acquainted with all the species, and 
then to submit them individually to careful analysis ; 
which enabled me to ascertain how far general exter- 
nal resemblance and structure go together. Of such 
characters which combined the species best, I selected 
the most remarkable. Whether this has been done 
with judgment it is for others to decide. I may how- 
ever take the opportunity of expressing my conviction 
that no one can understand Roses, unless well ac- 
quainted with them in a living state. That this incon- 
venience, which is undoubtedly great, may be in some 
