322 
WILLIAM A. MURRILL 
various herbaria without complete success. Carbon bisulfid has been 
mainly used in this country, but the results are not satisfactory. Cor- 
rosive sublimate, so extensively employed for flowering plants, is not 
only valueless but decidedly harmful to many of the higher fungi, 
since it alters or destroys their surface characters and often changes 
their substance to a marked degree. It is much better to lose some 
specimens than to have the whole collection thus altered. In the 
case of large woody specimens, also, it is very difficult to secure suf- 
ficient penetration to preserve the interior portions. 
The substance I have used with great success is naphthalene flake, 
of the best quality. Experiments conducted here have shown that 
adult insects are killed in a few hours when placed in a box with this 
substance, and it is probable that those emerging from the pupa stage 
succumb in less time. Specimens are treated when first obtained, and 
those peculiarly susceptible are kept in an atmosphere of naphthalene 
more or less all the time. In going through the collections, when a 
packet or box is found containing insects, a spoonful or more of naph- 
thalene is added and the incident closed. Possibly there are insects 
not yet acquired or some that do not thrive in this region that are not 
amenable to this treatment, but it has been more satisfactory here so 
far than any other method I have seen tried. 
All fungi found upon leaves are treated with corrosive sublimate. 
This is done chiefly to preserve the leaves intact, the fungi being so 
small that, with few exceptions, insects would hardly do them serious 
damage. All other fungi, particularly the conspicuous forms known as 
mushrooms, bracket fungi, etc., are placed in boxes with naphthalene 
flake for several weeks or longer, according to the season, before dis- 
tributing them in the herbarium. Groups peculiarly liable to attack 
are examined once or twice a year and fresh naphthalene added when 
necessary. After a box collection has been once cleared of pests, it is 
not so difficult to keep them out, with a fair amount of precaution and 
vigilance. 
The Arrangement of Illustrations 
The ideal herbarium contains specimens arranged in a single series, 
with all notes and illustrations classified with the specimens. The 
maintenance of more than one series is both a complication and an 
aggravation. However, throughout most of Europe, illustrations 
are kept in a separate series, just as exsiccati usually are; and I might 
remark that both exsiccati and illustrations should be in duplicate so 
