1960] 
Wheeler — Ant Larvae 
If overstained the integument can be completely decolorized by 
leaving it in a i% solution of potassium hydroxide for several hours. 
It can then be washed and restained. 
Dehydration 
After staining, the exoskeletons are transferred to 95% alcohol 
(about 3 ml), in which they remain for about an hour. At the end 
of this period eight drops of carbolxylol ( = 3 parts xylol and 1 part 
melted phenol crystals) are added every five or ten minutes until 48 
drops have been added to the alcohol. If the carbolxylol is added too 
rapidly the exoskeletons may collapse and become distorted; they can 
be restored by transfer to 95% alcohol. If oil droplets separate from 
the alcohol, too much water has been carried over from the stain ; 
the integuments are transferred to fresh 95% alcohol. 
Clearing 
From the mixture of carbolxylol and alcohol the integuments are 
transferred to pure carbolxylol and left for 15 to 60 minutes; then 
to xylol in a culture slide (or if large, in a staining dish). Add a drop 
of thin Canada balsam every 15 minutes, allowing the xylol to evapor- 
ate meanwhile. 
Mounting 
When the balsam in the culture slide attains the same consistency 
as that which is being added, a large drop of the latter is placed on a 
slide and the exoskeleton is transferred to it. At this time medium to 
large specimens are surrounded — or at least flanked — by supports of 
some sort. We use fragments of broken slides which are of about the 
same thickness as the depth of the specimen. If it is obvious that the 
exoskeleton will not remain in the desired position, supports (such 
as a fine glass rod or fragments of cover slip) may be placed under the 
low part. 
Positioning 
With needles dipped in xylol the integument is now arranged in the 
proper position for drawing (discussed below). Since the balsam must 
be soft at this stage, the specimen will rarely remain in precisely the 
desired position ; hence the slide is allowed to rest flat in a covered con- 
tainer (e.g., a petri dish) for 24 hours. 
If the specimen then needs rearranging, this is done under a stereo- 
microscope with needles dipped in xylol. If the balsam is too firm a 
drop of xylol is put on it and let stand a few minutes before using 
needles. If it is apparent that the specimen will not remain in the 
