PLATE 1 
A. —Stems of false dandelion, Hypochaeris radicata , showing galls produced by 
the insect Aulax hypochaeridis Kieff. These are shown to distinguish them 
from the galls caused by the stem nematode, Tylenchus dipsaci. 
B. —Immature flower heads of false dandelion showing stem nematode swell¬ 
ings at the base of the flower head. 
C. —Normal flower heads of H. radicata; compare with B. 
D. —Sections through nematode-infested heads of H. radicata. Note the dis¬ 
colored receptacle, which contains hundreds of nematodes. 
