498 
POPULAR SCIENCE REVIEW. 
and are found growing throughout the whole of Europe, India, 
Africa, and New Zealand. “ In some parts of France, as in 
Poitou,” says Berkeley, “ it is simply necessary, in order to 
their supply, to inclose a spot on the chalky downs, sowing it 
with acorns. As soon as the saplings attain a growth, of a few 
years, the truffles appear, and a harvest is obtained for many 
years successively without further trouble.” Thus it appears 
that the culture of truffles is reduced to as simple a process as 
that of most plants ; but the apparent necessity of first plant- 
ing acorns has given rise to much misapprehension on this head ; 
for, in a French journal of science last year, a paper appeared, 
■written with the avowed object of “ clearing up the mystery 
which has so long surrounded the reproduction and artificial 
propagation of the truffle,” which, the writer says, “ is simply 
an underground species of oak-apple, produced by an insect on 
the rootlets instead of the leaves of the oak. The white oak 
is chiefly selected, and the young trees should be planted in a 
light porous soil, — a sandy or chalky soil is the best, so that the 
flies may find ready access to the roots. A southern aspect, 
■with plenty of sun and air, is the preferable situation both for 
trees and flies. There are as many varieties of these special 
flies as of truffles. They are mostly of a small size, and make 
their appearance after rain has fallen, and during the warm 
months of July. In August and September they penetrate to 
the roots of the trees for the purpose of depositing them eggs. 
After the small puncture has been made by the fly, this portion 
of root separates from the parent tree, and goes on increasing 
in the same way as the oak-apple, and in process of time becomes 
food for the larvae ; which are hatched about March. Then com- 
mences the work of destruction, as the larvae eat their way out 
of their winter prison, and pass through the usual metamor- 
phoses to that of the perfect fly.” The paper concludes as 
follows : “ that by a careful application of the foregoing know- 
ledge large plantations in the department of Yaucluse have 
been for a long period very profitable to their owner, A. W. 
Falon ; and by digging up the roots with the chrysalides at the 
proper time, they have been transported in boxes to form other 
plantations equally profitable.” 
The microscope clears up all this ingeniously woven tale, and 
we read by its aid the life history of this remarkable under- 
ground plant ; and although so extremely simple in its organ- 
ization, we see in it the secret manner in which nature builds 
up her most complicated vegetable structures. A section from 
the fleshy-looking mass cut very thin, and viewed under a power 
of 250 diameters, is found to be chiefly composed of cellular 
substance, the interspaces of which are filled up by jointed 
filaments, homologous to the mycelium or spawn of other fungi, 
