MOUNTING THE PROBOSCIS OF A FLY.—PREPARATION. 21 
were reproduced of the same size that they were drawn, with a result 
not very pleasing to the eye of a critic. 
The next blocks were more successful, and may be found as Figs. 
18, 19, 20 and 21 on page 268, Vol. II. ; they were over-reduced, 
but still the reader will have some difficulty in distinguishing them 
from ordinary wood-cuts. The plate in the November number is a 
facsimile of a careful drawing by Mr. Stanley, while the papers 
upon the “ Human Eye” in the same number has 1o illustrations 
produced by the same process. 
The value of Photo-zincography for illustrating Microscopical 
literature having been established, it behoves us to show our readers 
how the matter should be accomplished. 
The drawing should be made upon cream laid paper with an 
ordinary pen, and of a size three diameters as large as is finally 
required in the block. ‘Those upon page 344, 1882, were drawn, 
so that a line reaching from the outside edges of the capsule of H. 
sericeum and the leaf of A. /ucens measured exactly 11 inches, and 
the result is perfectly satisfactory. 
The blocks in the present number, illustrating the article on 
“‘ Moss Development,” have been reduced to one-third their original 
size, and to show the reader exactly how the original should be 
drawn, we have reproduced Mr. Stanley’s drawing of Fig. 12, and 
which will be found on page 20 as Fig. 14. 
Our readers may now see how they can aid us, and how we may 
be able to aid them. We shall be happy to illustrate any paper we 
deem of sufficient interest to the majority of our readers if drawings 
are sent to us, prepared as herein described. 
MOUNTING! THE, PROBOSCIS OF AF bY. 
PREPARATION. 
By G2 -W. LorrHouse. 
ILL the fly by putting it into a bottle containing a little car- 
bolic acid that has been rendered fluid by the addition of a 
drop or two of water,—no more water should be used than is 
necessary. Acid, so prepared, may be obtained from Mr. Ward. 
Cut off the head, and place it in a small porcelain saucer and 
cover with a little of the acid, which must be changed about every 
other day for say a week, or until it ceases to become coloured. 
The tongue will then, in most cases, be found to be protruded, or 
may be forced out by slightly pressing the head. 
L-xpanding.—To expand the tongue, it should be placed in the 
centre of a glass slip, and put upon a piece of wood, about 5 inches 
