1921] Giffard: Male Genitalia of Delphacide 139 
ordinary test tube for a few seconds only. The success of the method 
depends largely on the boiling precess, for if it is boiled too long the 
clearness of structural detail is spoiled, whilst if it is not boiled enough, 
much fatty matter will remain attached to the organs to be observed, 
thereby causing scme slight inconvenience in their further dissection 
and observation. It is, however, far better to underboil than otherwise. 
The student will soon learn to detect by the size, condition and appear- 
ance of the pygofer just what time is required in this boiling process. 
From the Caustic Scda the specimen is immediately transferred to 
water in order to wash and clear it. For this, it appears preferable to 
use a concave glass slide, so that the object may be kept under better 
control whilst under the binocular microscope. During this clearing 
process in water, the genital organs should be dissected out from the 
pygofer. This is done by means of fine needle points, with handles 
attached, holding the pygofer down with one needle whilst inserting the 
other through its anterior opening and pushing outwards the organs 
until all these are plainly visible. If it is intended to make a micro- 
scopic slide of the genitalia further manipulation and dissection under the 
binocular will be necessary in order to free the organs from the 
diaphragm or wall of the aperture of the pygofer, but for ordinary 
purposes of identification the pygofer together with the protruding 
organs can, without further process, be transferred with a very fine 
camel’s hair brush or the point of a needle to the card point on which the 
insect specimen is mounted. Care must however be taken not to crush 
or smother the parts during manipulation and the mounting on the card 
point must also be carefully done, otherwise the organs will appear 
distorted and useless. Before mounting in balsam it is necessary to 
transfer the pygofer and genital organs into absolute alcohol in order 
to dehydrate and harden these. A few minutes only is required and 
the organs should then be cleared by transferring them from the alcohol 
to clove or cedar oil. In either one of these latter they may remain for 
a few hours, if necessary, but if speed is desired, four or five minutes is 
all that is required. 
Some have objections to the microscopic slide process, as the slides 
have to be kept apart from the cabinet specimens: and again others 
claim that there is apt to be an absence of detail as shown by the ‘‘card 
point” system. To these may be suggested another and very acceptable 
method of permanently disposing of their dissections and at the same 
time keeping these attached to, or alongside, the insect Specimen in 
their cabinets. This system has been called the Balsam card cell! 
process,* and it has been used to an appreciable extent for the mounting 
of the genitalia of type specimens. For the purpose, rather stout 
Bristol board mounts of uniform size should be used (See Figure 4). 
* Similar cells to these can be used without balsam for mounting delicate 
_ types, the insect being fastened with a small drop of clear gum to the bottom cover 
glass. Dr. David Sharp has types of small Staphalinide so mounted which can 
be viewed dorsally and ventrally under a fairly high power. The probability of 
damage or destruction of such specimens is greatly reduced by using this method. 
