156 THE OAK 
branches owing to the paucity of water at those parts, 
the parasite taking much of that which reaches the 
injured place, and the impoverished wood allowing less 
to pass than it would normally have done. 
Among the fungi there are several enemies to fhe 
oak-tree. The leaves are attacked by Phyllactinia, one 
Fie. 41.—Loranthus europeus. A. Lower part of stem 
attached to branch of oak, both denuded of cortex. B. 
Longitudinal sectionthrough one of the haustorial strands, 
showing its progress, year by year, as the branch thickens. 
c. Transverse section, through a branch which has long 
been badly infested with the Loranthus; aa, dead re- 
mains of old haustorial strands; 0b, young Loranthus 
plants developed as buds from the older ones. The 
asterisks mark still younger specimens. (Hartig.) 
of the mildews, which forms white networks, like spiders’ 
webs, on their surfaces. Numerous small ascomycetous 
fungi are found on the dying and dead leaves, but these 
do not directly injure the living tree. | 
Other fungi are found in the cortex, and one of the 
most interesting of these is a red Nectria, the spores of 
