234 MISSOURI ‘BOTANICAL GARDEN, 
in the former one. All of the works embraced in the two 
lists will be found together on the shelves, arranged in one 
alphabet, or represented in their proper places by dummies 
showing their location. 
The aim has been to make this catalogue both useful 
and accurate. Unusual difficulties are met with in dealing 
with older works, and it is hoped that users will find that 
a solution of these problems has been approximated. No 
single bibliographic work sheds sufficient light on all the 
dark passages that must be threaded in such an undertaking, 
and there are many cases in which little or no help can be 
obtained in answering the many nice questions presented. 
The works most frequently consulted have been those of 
Seguierius, Pritzel, Haller and Meyer. The patient erudi- 
tion displayed in these guides has enabled me to reduce the 
number of errors which without such help would have ap- 
peared in this catalogue. I wish to record here also my 
grateful acknowledgment of the courteous assistance and 
advice given by Dr. William Trelease. 
This catalogue follows closely the style and arrangement 
employed in the older one. The intention has been always 
to reduce authors’ names to the nominative case, following 
the idiom of the language in which the title-page is printed, 
and this has resulted frequently in the appearance of an 
author’s name under several different spellings. Where 
this practice has caused the separation of the works of an 
author, or has thrown them where they would not ordi- 
narily be sought, cross-references have been freely employed 
to aid the user of the catalogue. Indeed, in the entire 
list, I have preferred to err rather in the way of using too 
many cross-references than too few. 
It will be observed that no liberties in the way of para- 
phrasing or changing titles have been taken, except in a 
few cases where the fact is shown by the use of brackets. 
An exact rendition of the author’s name and the title, in an 
intelligible form, has been the aim in all cases. Any mat- 
