1960] 
Wheeler — Ant Larvae 
93 
coordinate paper is not available or if the squares are not of the desired 
size, it is not difficult to construct a coordinate grid on plain paper. 
When the eyepiece grid is properly placed with reference to the 
image and the coordinate system is established on the paper, we are 
ready to start drawing. 
The dimensions and proportions of the drawing are established by 
short marks across the lines of the coordinate system in the appropri- 
ate places. The main outline is constructed by joining these inter- 
sections with freehand lines. Structures inside or outside the main 
outline are treated in approximately the same way, but more freehand 
drawing is required because fewer squares are involved and smaller 
parts are likely to be wholly inside a single square. It is not necessary 
to complete all fine details at this stage. 
The drawing is placed on a tracing table, a sheet of thin drawing 
paper (e.g., Ledger Linen) is laid on it; the drawing is copied onto 
the drawing paper in India ink with curve-pen (Keuffel and Esser). 
Finer details are drawn with a Hunt Mapping Pen No. 104. 
In the case of bilaterally symmetrical structures (e.g., head in 
anterior view) only one half is drawn, with a vertical matching line 
down the middle. After this half (but not the matching line) has 
been inked the pencil drawing is turned over on the tracing table, 
matched up to the first half and then inked. 
Most of our drawings are orthographic projections of opaque ob- 
jects (even though the integuments studied are actually transparent). 
Only structures on the near side of the plane of the outline are drawn. 
For example, in a side view of a larva the outline represents the 
imaginary middorsal and midventral lines; hairs and other parts 
attached beyond (= below, in the field of the microscope) the plane 
of these two lines are not shown. To our rule of assumed opacity a 
few exceptions are made, e.g. dark-colored structures overlaid by 
translucent tissues. 
We have found 120 mm to be a convenient length for a drawing 
of the entire larva. The plane of projection includes the middorsal 
line (imaginary), the midventral line (imaginary), the middle of 
the anus and the middle of the bottom of the labium. It is convention- 
al to view the larva from the left. But if for any reason it has been 
drawn from the right, the original drawing (on co-ordinate paper) 
can be turned over on the tracing table before inking. 
The head is drawn in full-face (i.e., anterior) view. The plane of 
projection passes through the uppermost line (imaginary) of the 
