46 
bear in mind: Ist, the more rapidly plants are dried, the better 
they will retain their colors ; 2nd, the first two days that plants 
are in the press are of more importance than all the subsequent 
time. 
Two or even three changes of the driers during the first 24 hours 
will accomplish more than a dozen changes after the lapse of se- 
veral days. The most perfect preservation of the beautiful colors 
of some orchids which I have ever seen, was effected by heating the 
driers and changing them every two hours durin g the first day. 
For Jess delicate specimens, two changes the first day, one change 
a day for three or four days after, and subsequent changes at grad- 
ually increasing intervals, will suffice. It is often difticult to tell 
whethera plant is thoroughly dried or not. This may sometimes be 
ascertained by pressing it for a moment against the check. If the 
cheek feels cold on its removal, the plant is still moist. 
Other methods of drying plants are sometimes employed, but are 
less convenient or less adapted to a large number of specimens. _ 
One is to place the plants and driers between sheets of wire 
gauze protected on the edge with arim of stout iron wire, and 
hang the whole in the sun and wind, without any subsequent 
change. Only a small package of plants can be dried in this way. 
Another is to abstract the chief part of the moisture of the plants 
at the outset, by placing them in some convenient vessel, and 
sprinkling or sifting dry and warm sand over them ; at the end of 
a day or so, they are to be removed from the sand and put in the 
press. 
Thad nearly forgotten one point of the first importance : do not 
neglect, at the earliest opportunity, to insert in each sheet a label 
bearing the name of the plant, if already made out, but, at all 
events, the place and date of collection, together with notes of the 
locality in which it was found. This is often left, to the subsequent 
sorrow of the botanist, until these particulars have escaped the 
memory, and half the value of the specimen has consequently been 
lost. F. J. B. 
<< 74, Spirodela_ polyrrhiza— Prof. Hegelmayer of Tiibingen has just 
given us in the Botanische Zeitung of Sept. 22 & 29, 1871, a most in- 
teresting addition to the very thorough monograph of Lemnace®, 
published by him three years ago, by his account of the organs of 
fructification of Spirodela polyrrhiza from the specimens recelv 
zon Mr. Leggett, and has illustrated it thoroughly by numerous 
_ figures. : 
He premises it by stating that, according to his present lights, he 
must consider the organs of the flowering Lemnz as constituting 
single hermaphrodite flowers, consisting of a pistil and two lower 
stamens, the third upper one being regularly abortive, and sub- 
tended by a bract (what was called the spathe. ) < 
_ He then minutely reviews the flowering organs of our Spirodela, 
which are in the bud surrounded and enveloped by the membra~ 
_ neous bract, bearing erystal and pigment cells, and which opens 
by a small apical slit. The second or posterior stamen -often 
