FUNGI. 421 
new trees in situations where old trees have 
drooped and perished. Compost, consisting of 
decayed vegetable substances, and the fallen 
leaves and twigs that strew the ground in shrub- 
beries and plantations, by harbouring the spawn 
of fungi, may prove the source of serious mischief ; 
and many diseases of cultivated crops may be 
traced to the existence of spawnin the manure. To 
the farmer and gardener, therefore, the nature and 
effects of fungi should be subjects of special study, 
seeing that they are so powerful for evil. 
In concluding this notice of the destructive 
fungi, mention may be made of a peculiar form of 
Penicillium or mould, which is almost invariably 
present in the solution of copper employed in the 
process of electrotyping. It proves an intolerable 
nuisance, inasmuch as it is often invested with a 
silver coat, and injures the beauty and the finish of 
the articles which are subjected to the process. 
It is extraordinary that the poisonous nature of 
the solution does not destroy it; but it has been 
often observed that various species of mould 
luxuriate in solutions of arsenic, opium, and other 
poisonous chemical substances, which would prove 
instantly fatal to all other plants. The factories 
of India occasionally suffer greatly from the pre- 
sence of fungi on extracted opium. 
After this detailed description of the specific 
