Microscopical Society of Victoria. 
69 
finally mounting them, it is easier to judge as to whether they 
are sufficiently clean to be preserved. I have re-mounted old 
slides which were not satisfactory by lifting the cover and 
thinning the balsam on both slide and cover with carbolic acid, 
and then re-arranging the diatoms and proceeding as before 
described, I have also obtained half-a-dozen slides of distinct 
species, besides duplicates, from a single purchased slide of mixed 
material, in a similar manner. The same process Is of course 
equally applicable to any small hard objects, such as Radiolaria , 
plates of the ITofothuridfc , &c., when different species are so mixed 
with each other or with sand as to make it undesirable to mount 
them without selection. I have mounted diatoms in symmetrical 
groups in this manner, but the valves cannot be relied upon to 
maintain their exact relative position when the hard balsam in which 
they are imbedded has become softened by the contact of the soft 
balsam afterwards added to it. Slides mounted after either of the 
methods described should always be kept in a horizontal position, 
otherwise any of the objects that may be free will probably sink 
by their own weight towards the lowest part of the slide before 
the balsam has had time to harden. 
If a finder is required, the simplest plan is to place a hair or a 
fibre of coloured silk in the balsam before hardening, in such a 
way as to extend from near the objects to the edge of the cover. 
his is easily found under any power, and can be followed along 
till the end of the thread and the objects come into the field of 
view. 
Notes on Insect Eggs . By W. M. Bale. 
[Read 27th November, 1879.] 
I have examined the organisms on a piece of bluestone forwarded 
by Mr. Dawson from Camperdown, and find them to be the eggs 
of a mite of the family Trombidino. The following remarks from 
Dr. Duncan’s “Transformations of Insects” so evidently apply to 
them, or a closely allied species, that there is little room for further 
remarks: — 
“ M. Duges has given some most interesting details concerning 
the structures and metamorphoses of the Tracheary Arachnida in 
