176 Annals Entomological Society of America  [Vol. XIV, 
varies with the degree of chitinization, but I have found it takes much longer than 
usually estimated to reach a degree of clearness which gives the best results. 
In fact, after soaking the parts in cold potash for a day or so, I have usually boiled 
them for from three to six hours in the same solution. In this process the cotton- 
plugged vials are very useful; for if the cotton plug is made just tight enough it 
will not be raised by the boiling and this prevents the boiling over so often 
experienced with materials in a test tube. The shell vials in a small staining dish 
may be placed in a casserole; or a cluster of them, tied with cord to keep them 
upright, may be placed directly in the casserole. It is a wise precaution to use a 
shallow casserole, in which the tops of the vials will come above the edge, so that 
the contents will not be lost or mixed by the liquid in the enclosing dish boiling 
over into the vials, or vice versa. 
(5). When the parts have been thoroughly cleared, the vials are lifted 
separately or collectively from the potash and placed in a second dish containing 
distilled water, and thoroughly washed. Two or three changes are sufficient, 
especially if the fresh liquid be added through the mouths of the vials, by means 
of a pipette. 
(5a). If the specimens are large and not thoroughly cleared, they may 
now be improved by placing for some hours in glacial acetic acid. This 
dissolves any fat that may have escaped the action of the potash and also 
any crystals of potash that may have evaded the washing. 
(5b). Again wash thoroughly in water. 
At this point the worker has a choice of several methods successively 
described: 
A. 
The specimen can now be placed on a microscope slide with a few drops of 
water and a cover glass, for temporary examination. It can be kept indefinitely 
in splendid condition in a small vial of equal parts 95% alcohol, glycerine and water. 
If a permanent mount is desired, method B, C or D must be followed. 
5: 
If the slides are not to be transported, and can be protected from rough 
handling, a very satisfactory plan is to mount them simply in a drop or two of 
glycerine. This has the advantage of allowing one to move the specimen about 
very freely under the cover glass, to study it in all-aspects. To make a really 
permanent mount, however, follow either method C or D. 
Co ID). 
(6). The vials are transferred to a (6). The vials are placed in a jar 
dish containing glycerine, for an hour containing a stain made of one gram 
or more. Proceed with step 10. of acid fushsin and 25 cc. of 10% 
hydrochloric acid in 500 cc. water, 
for from ten to fifteen minutes. If 
the strength is reduced to half, the 
specimen can usually be safely left 
over night. 
(7). Wash in water and 
(8). Pass through several grades 
of alcohol, as 30%, 85%, 95%, two 
changes, and into absolute alcohol. 
(9). Transfer a few at a time into 
xylol or carbol-xylol, so that no one 
remains longer than about a half hour, 
before you can arrange it on its slide. 
(10). Prepare a microscope slide by scratching on it the number of the 
genitalia to be mounted, or by attaching a gummed label which may also bear 
the name of the insect, by whom determined and also locality and date if desired. 
