884 . NOTICES OF BOOKS. 
here divided, the limits of the species are clearly definable ; in others 
it is “extremely doubtful whether some which the author still retains 
ought to be admitted as anything more than forms of one common 
type, as, for example, among the Plurituberculata. It will also be 
found that supposed species are absolutely reduced without hesitation 
to au extent which the author once thought improbable; but many 
months? very careful critical re-examination of all the copious materials 
at his command leaves no doubt upon his mind that at least those 
supposed species which are now cancelled ought never to have been 
.. elevated to that rank ; he must, however, add that the badness of ma- 
terials, the imperfection of drawings and descriptions, and the misin- 
formation so common in gardens concerning countries, have rendered 
such errors unavoidable, even if no account is taken of the haste with 
which a botanist working without leisure must necessarily act.” 
Throughout the monograph we meet with similar expressions of 
. caution and philosophical treatment of the subject ; and above all, we 
have to admire the candid manner in which the author speaks of his 
own groups and sections. Some of these, though indispensable to the 
. determination of the species, and the result of the most painstaking 
; analysis and study, being after all pronounced wholly artificial. 
- We need hardly say that the author's habit of never throwing his 
words away is of the most essential value in a work of this kind. The 
descriptions are remarkably clear and terse, and there is no attempt 
in the English remarks to dilate upon trifles, or to give a fictitious 
value to a doubtful species, by over-describing organs that vary iu 
every specimen: this gives an appearance of brevity to the diagnoses 
and descriptions, which however, when applied to the specimens, prove 
to be ample and lucid as well as accurate and skilfully drawn up. 
In acknowledging with his accustomed eagerness the assistance he 
as received from others in the elaboration of Oncidium, Dr. Lindley 
ays a well-merited compliment to Professor Reichenbach, jun. :—‘ He 
uld add, that in the revision of this genus his thanks are not only 
1e to his usual correspondents, but most especially to Professor H. G. 
Reichenbach, jun., of Leipzig, a most acute and experienced orchido- 
ist, without whose invaluable assistance it would have been impos- 
aaa Re : we s gets published by Conti- 
