90 
Psyche 
[December 
desired position, supports (fine glass rods or fragments of cover slip) 
may be inserted at this time. If supports were placed earlier, they may 
need readjustment. Shifting the retaining walls will sometimes correct 
the position of a specimen. After the rearrangement is completed more 
balsam is added if necessary to cover the specimen. 
It is sometimes necessary to rearrange a specimen on half a dozen 
successive days. Once a specimen has remained in the desired position 
for 48 hours and is completely covered with balsam, the technique is 
considered finished. 
If material is abundant we regularly make two kinds of mounts of 
each size and caste of each species: (1) an entire exoskeleton in side 
view; (2) detached head in full-face view, with the remainder of the 
exoskeleton ventral side up (or, if the head is applied to the ventral 
surface, the whole exoskeleton ventral side up). Other kinds of 
mounts are made whenever necessary. 
For a side view an entire exoskeleton with the left side up and in 
strict profile, i.e., the middorsal line, the midventral line, the middle 
of the anus and the middle of the labium are all in the same plane. A 
good check is to be sure that the left spiracle of each somite is directly 
above the right spiracle of the same somite. It is conventional to show 
the entire larva viewed from the left side. Actually it doesn’t matter 
which side is up. If for any reason (e.g., damaged left side) an in- 
tegument is mounted with the right side up, it is a simple matter to 
reverse the original drawing. 
The exoskeleton of the head is mounted in full-face (i.e., anterior) 
view. To accomplish this the uppermost line (imaginary) of the oc- 
cipital border is set in the same plane as the lowermost part of the 
ventral surface of the labium. 
When the head is applied to the ventral surface of the body (i.e., no 
neck), it is often possible to get it in the correct position by mounting 
an entire integument ventral side up. In most genera, however, it is 
necessary to cut off the head (either alone or with a portion of the 
prothorax) and mount it separately. 
It is often necessary to prop up the ventral part of the head on 
fragments of cover slip, but only very large heads require retaining 
walls. 
After the head is removed, the remainder of the integument is 
mounted with the ventral side up by following the procedure for the 
entire integument (see above). 
