INAUGURAL ADDRESS. 13 
considerations press on the trained observer, only one to be 
touched on here. Can the time approximately be determined 
when the Diptrodon stamped in gigantic paces our plains, and 
when the Thylacoleon roared in pursuit of other marsupials, now 
exterminated ? 
One of the most remarkable of objects within the whole range 
of biology is that of Symbiosis, the unexpectedly wide extent of 
which through the empire of plants having lately been demon- 
strated by Professor Beccari—the hospes not proving detrimental 
or often not even injurious to the host. Professor Frank very 
recently discovered that fungus-growth of quite peculiar kind at 
the extreme ends of the root fibres in oaks, beeches and trees. 
allied to them, mediates the nutrition of them as a necessity. 
Could all this be merely casual? The Azolla, nourishing a micro- 
scopic alge, is an example near to us, just as in other but similar 
respects the native evergreen beech. 
At the very time, when I left Europe, forty-two years ago, Count. 
Suminski discovered, to the surprise of many of us, the antherid- 
ous and archegonous organs on the minute prothallus of ferns ; 
but whether and how genetic relation exists between the primordial] 
and the subsequently-developed sporangious organs on fern-fronds 
has never yet been traced or explained ; and this is all the more 
mysterious as regards fern-trees, such as abound here, when years 
‘intervene between the production of the prothallus and that of 
the spore-bearing caselets. See further the vast significance of 
what, at first thought, may appear a mere trifling matter. 
A small fly (Lestophones tceryae) was not long ago noticed as 
antagonistic to the coccid-insect Jcerya purchasi, by the very 
observant Mr. Fraser Crawford, of Adelaide, though a closely 
allied fly, Zastophonus monophiebi, infests mainly, if not exclusively, 
another coccid, the Monophilebus crawford, as shown by Mr. F. 
A. A. Skuse, so that even in introducing the particular Diptere 
needed for subduing the Icerya very discriminative entomo- 
logy must be brought to bear for coping with an evil of quite 
dreadful dimensions in Californian orchards, not to speak of what 
with the less powerful Coccinellides can be done. Thus the 
Agricultural Department of Washington found it necessary to 
send a professional entomologist purposely to Australia, in order 
that the Lestophones be established also on the other side of the 
Pacific Ocean, to restore thus far “‘the balance of nature;” just as. 
in another remarkable instance the vines of the United States are 
largely reared in Europe and elsewhere now for their immunity 
to the Phylloxera vastatrix, which from America invaded other 
countries. Perhaps this parasite could likewise be subdued by 
other insects, such as would not attack the vines. If so, a question 
would be solved involving almost the whole interest of rural 
prosperity in many wide regions. So then a new special field is. 
opened anywhere for entomologic observations, with a prospect. 
held out of high substantial reward. 
