426 FIRST FORMS OF VEGETATION. 
of the atmosphere, forms sulphuric acid, the only 
chemical poison destructive to moulds and mil- 
dews. 
Fungi, owing to their cellular and perishable 
nature, do not usually occur in a fossil state. 
Some slight traces of them, however, now and 
then occur among the relics of a former state of 
things. Species of mould have occasionally been 
found in the amber beds of the tertiary formation— 
having been deposited and developed on the re- 
sinous juices of the amber pines, just as filaments 
of mould are often seen at the present day adher- 
ing to the gum of apricot and cherry trees. These 
tiny plants, identical as they are with the common 
green and blue moulds that infest our cupboards, 
leave us no room to doubt that fungi were as pre- 
valent and destructive in former epochs as they are 
now. M. Goeppert, who has examined minutely 
the amber of various lands, has detected in it, 
besides moulds, fragments of mosses, hepaticze, 
and lichens, perfectly preserved, as in a mummy 
case,—-the sole insignificant relics of that vast 
array of cryptogamic plants, which helped to 
preserve the balance between the kingdoms of 
the ancient world. Nature by this curious pro- 
cess of embalming, has perpetuated that which 
a breath of wind was sufficient to destroy, and 
“moulded into a geologic specimen what a 
