416 FIRST FORMS OF VEGETATION. 
cause; while in Ceylon the coffee-plantations, in 
the south of Europe the olive-trees, and in Syria 
and China the mulberry-trees, have sustained of 
late years immense damage from an unusual 
development of black mildews. Few objects, it 
may be remarked, are more beautiful under the 
microscope than the wheel-shaped, ray-like pro- 
cesses which radiate from the seed-bearing organs. 
A species of this family, called Fusarium mori, is 
produced in such abundance on the leaves of the 
mulberry, in Syria and China, as materially to 
diminish the supply of food provided for the silk- 
worm. 
But it is not only in food and luxuries that man 
suffers from the ravages of fungi ; he also suffers 
in his property. Builders have painful knowledge 
of one or two species, known under the common 
name of dry-rot. This most destructive plague is 
usually caused in this country by the Merzulins 
lachrymans (Fig. 51). It occurs on the inside of 
wainscoting, in the hollow trunks of trees, in the 
timber of ships, and in the floors and beams of 
buildings in moist, warm situations, where there 
is not a free circulation of air. It appears at first 
in round, white, cottony patches, from one to eight 
inches broad, which afterwards develop over their 
whole surface a number of fine yellow, orange, or 
reddish-brown irregular folds, most frequently so 
