268 
did tlie lime alone without the copper, as a trial demonstrated. There 
seems to be some mutual reaction between the Bordeaux and the lichen 
substance, probably the fungous part, since a test with unicellular algse 
gave no such results. This point is worthy of further investigation, and 
is of interest on account of the possibility of its throwing light on the 
general question of the action on fungi of the copper compound in Bor¬ 
deaux mi x t ure and in other insoluble copper preparations. Microscopi¬ 
cal examination of a small portion of a lichen tliallus which had been 
treated with Bordeaux mixture and had turned yellowish and dried, 
showed no marked changes. The chlorophyll, however, had turned a 
brighter yellow color, and to this is probably due the general change 
of color. 
SUMMARY. 
(1) Bordeaux mixture is an effective remedy for lichens on pear 
trees. 
(2) Eau celeste, chloride of lime, (1 per cent solution) and bichloride 
of mercury, (one-tenth of 1 per cent solution) proved unsatisfactory. 
(3) There seems to be a reaction between the lichens and the Bordeau x 
mixture in which thefiocculent precipitate constituting the active princi¬ 
ple of the latter is probably partially dissolved and absorbed. As a 
result the lichens assume a yellow color and die. 
DESCRIPTION OF PLATES. 
Plate XXX. A Bartlett pear tree near Scotland, Va., infested with lichens. From 
a photograph taken October 19. 1892. 
XXXI. Bartlett pear tree in the same orchard which had been treated with Bor¬ 
deaux mixture, showing the dead and shriveled remains of the lichens. 
From a photograph taken October 19, 1892. 
NOTES ON FOSSIL FUNGI. 
By Joseph F. James. 
The enormous number of species and individuals of living fungi pre¬ 
supposes their existence in the past. But their evanescent nature and 
their peculiar structure render their occurrence in a fossil state ‘com¬ 
paratively rare. There is great difficulty in keeping many of them 
with all the care and experience of botanists, and it is natural to 
expect the vicissitudes of time will operate against rather than in favor 
of their preservation. During those periods of geological time when 
vegetation was mainly confined to the sea, we can scarcely expect to 
find fungi, so that not until the Devonian epoch need we look for evi¬ 
dences of their presence. Tbe Carboniferous period, however, with its 
