April, 1907.] Collecting and Preserving Thysanura. 
121 
proceeded for some time the glycerine should be changed fre¬ 
quently in order to dispense with as much corossive sublimate 
as possible. 
Boiling Absolute Alcohol.- This is another method 
which is particularly applicable for laboratory use. Place the 
specimens in a straight necked vial and pour over them boiling 
absolute alcohol. Leave for from five to fifteen minutes and 
transfer to 95% alcohol, and preserve permanently in 85%. 
The specimens when properly fixed may be left in this grade 
indefinitely without shrinking. The changes should be made 
between the different grades of alcohol about every ten or fifteen 
minutes. If it is desired to mount the specimens in balsam, 
xvlol may be added gradually to the absolute alcohol. Or on 
the other hand glycerine may be added and the alcohol allowed 
to evaporate. The alcohol may be used cold in the same man¬ 
ner as described above; however, there is less liability of shrink¬ 
ing the specimens if the temperature is raised to the boiling 
point. No more time should be occupied in transferring the 
specimens from alcohol to balsam than is ablsoutely necessary 
however, if the transfer is made too rapidly the specimens will 
cloud. Cedar or clove oil may be used in place of xylol with less 
liability of shrinkage. While balsam mounts are almost always 
shrunken they are almost indispensable for the detailed study of 
the claws, spring, and hairs of the insect. 
Sugar Jelly Mounting Media. —One of the best methods 
for examining the Thysanura is as follows: Specimens that 
have been in pure glycerine for a few hours are placed in a thick 
syrup consisting of apple jelly and glycerine. After staying in 
this syrup for an hour or so they are mounted in pure apple 
jelly in which a very small amount of carbolic acid or corossive 
sublimate has been added. The clearest jelly possible should 
be selected, melted, and a few drops of carbolic acid or corossive 
sublimate stirred in and then filtered through two or three 
folded filters. The cover glass should be rung with some gcol 
cement, Bell’s having proved most satisfactory, and afterwards 
finished with black enamel. This is a method that has been 
tried and found successful for mounting Papirius, and is the only 
means by which I have been able to preserve both their form 
and color. However, the utmost care must be observed through¬ 
out, giving the fixing agents plenty of time or the specimens will 
shrink destroying their correct form and color. 
Specimens may also be examined in pure cedar or clove oil 
which has been boiled down to a thick syrup. The only way 
such slides can be finished is by ringing them with Bell’s cement. 
This method is excellent for showing some of the finer details. 
Live boxes for these minute insects are verv easily and simply 
constructed, when one wishes to study their habit's in the lab- 
