130 
ith trypsin (5 c.c. of Benger’s liquor pancrea- 
ee 0-5 es om sodium carbonate gave 7 
much more variable but in effect substantially similar to those 
of pepsin. 
) i i i ; candulae on its 
Conclusion.—The life history of Phoma lavandu | 
host plant is simple. e overwintering of the fungus — 
spring infection of the host is by means of the occasiona 
. . ] 
spores which are produced in immense numbers. By the remova 
of all affected shoots as soon as noted, and if possible before 
pycnidia are formed, the disease may be kept in check. 
Summary.—A serious disease of the genus Lovet . 
caused by Phoma lavandulae, Gabotto, a fungus which is her 
recorded for England. 
In pure culture on nutrient media the fungus produces ihe 
thin-walled Pycnospores, hyaline thin-walled conidia—which late 
ome thick-walled and brown—and thick-walled brown 
chlamydospores. 
The thin-walled “pores germinate almost immediately, are 
little resistant to desiccation and are killed by frost. 
The thick-walled spores are fairl 
desiccation, and only 
be eliminated by free 
Y resistant to prolonged 
germinate after a resting period which may — 
zing or the action of pepsin or trypsin. 
All spore forms germinate freely in vegetable nutrient ne 
and the optimum temperature for the growth of the myceliu 
is about 18-200 ¢. 
The development of the 
tions indicating that its ori 
to the food supply, 
Infection experiments were carried out and demonstrated - 
pathogenicity of the fungus to the genus Lavandula and 
fact that the fungus is probably confined to this genus.” 
The fungus mycelium ramifies throughout the host ieee 
and causes the cortex and phloem groups to collapse. — oe 
Pf os pass from cel] to cel] through the abundant pits i 
walls, 
age F : “Var 
pycnidium is described and sane 
entation is conditioned by its rela 
immediately below the epi 
Tom the cortex. © Conidial formahian 
. he normal life cycle but chlamydospores are oc¢ 
sionally formed. 
