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Herr R. Klebs on the Fauna of Amber . 
intermediate forms between gnats and Brachycerous flies. 
Hagen has more recently given us a very exhaustive treatise 
on quite a small group of amber insects — the Psocidae ; while 
the ants have been examined by Meyer. Apart from a few 
small memoirs, this includes the whole of the work which has 
hitherto been done on this interesting subject. Berend’s 
work on the organic remains in amber, published in 1854, is 
of but little value for purposes of identification. 
The chief obstacle which has hitherto militated against the 
proper working out of these treasures, of such extreme import- 
ance for palaeontology and zoology, lay in the fact that the 
bulk of the material was not selected with sufficient care and 
was altogether insufficiently prepared. Kiinow was the first 
to polish the pieces of amber containing specimens in such a 
way that they can be examined with the microscope with 
almost greater facility than preparations of existing forms. 
It was owing to this that Hagen, in his recent work on the 
Psocidse, the material for which was entirely derived from the 
Kiinow collection, was able to furnish such interesting data 
for the phylogeny of this group from the Tertiary period to 
the present time. In preparing the specimens as much as 
possible of the surrounding amber was first removed, and 
then, after polishing, they were imbedded in a hard resinous 
matrix of approximately the same refractive index as amber. 
By this means the amber enclosing the specimen is perma- 
nently preserved from efflorescence and that loss of trans- 
parency, which have worked such havoc among old and 
valuable collections. Herr Klebs has so arranged this process 
that it can be employed for the preservation of blocks of 
amber containing a number of specimens, by which scientific 
examination is facilitated, while the specimens themselves are 
rendered very suitable for exhibition purposes in museums. 
After these introductory remarks Herr Klebs proceeds to 
summarize the results of his investigations. 
Among the creatures imprisoned in amber the Diptera are 
most numerously represented, and material to the amount of 
at least twenty thousand perfectly preserved examples has 
been collected. Nematocera and Brachycera are present in 
about equal numbers. The Pupipara and Aphaniptera are 
so far conspicuous by their absence. As regards the richness 
in species of certain of the genera represented in amber, it 
was found by Low that, for example, 
