94 Rhodora [June 
excess moisture can be taken up with a blotter or handkerchief and 
the glycerin-prepared tissue, whether delicate or indurated will not 
dry out. A further and great advantage is that the dissected pieces 
may be put away in an envelope on the herbarium sheet and will 
keep for reference — I do not know how long but at least for years. 
About three or four drops of glycerin to an inch of water in a small 
test tube (or to a teaspoonful of water) is the proper proportion. The 
parts to be dissected are dropped in this and brought to a boil. A few 
drops of glycerin placed on the object and a little boiling water added 
'answers the purpose about as well as test tube and alcohol lamp. 
The glass slides ruled in millimeter squares can be ordered from any 
dealer in microscopes and cost about two dollars, or those with finer 
lines with a row of squares ruled in tenths, about five dollars. The 
latter are necessary for mosses but not for flowering plants. It is con- 
venient to have the slide 5 X 7 centimeters, the ruled square, 20 X 20 
mm., in the center. Leaves or entire plants or portions of them 
may be drawn in the same way by laying the part to be illustrated 
on an herbarium sheet ruled in centimeter squares. For paper I have 
found the heaviest weight of linen ledger more satisfactory than any 
drawing paper. The heavy ledger paper permits a great amount of 
erasing without furring up under the pen. Before redrawing the 
erased place should be rapidly rubbed to a polish by means of some 
smooth rounded object such as the bone handle of a knife, otherwise 
the ink may spread on the scratched place. The pencil drawing when 
worked up to the best of one’s ability may then be “inked in,” using 
Higgin's India ink. For the beginner this is the trying part. Pen- 
and-ink is a much more difficult medium with which to express what 
one sees before him than is a pencil, but if the illustration is to be 
published, pen and ink is necessary unless one can afford to pay for 
wood-cuts or lithographs or is content with the usually unsatisfactory 
half-tone. Drawings for publications should be made at least twice 
the diameter the illustration is intended to be when printed, or, if 
one’s lines are unsteady, the drawings may be made three or four 
times larger, to allow for greater reduction. It is necessary to keep 
in mind, however, that in so great a reduction spaces as well as lines 
are reduced and that unless kept well apart adjacent lines will run 
together and cause black spots or smudges, and also that the lines 
unless fairly heavy may appear broken. By practice one learns to 
make firm lines and a reduction to one half diameter effaces small 
