58 
Mycologia 
epidermal cells, while in the conn it becomes intracellular, enter- 
ing both the storage cells and the vascular bundles. The short 
conidiophores emerge from the stomata. While they are usually 
simple and bear a single conidium, a second one may be borne in 
the typical cymose manner of Phytophthora. The conidia are 
quite large (18-26 X 30-60 fx or larger), somewhat pyriform, and 
more variable both in size and form than in most species of the 
genus. There is a broad blunt apical papilla. 
When mature the conidium “ contains a single vacuole of vari- 
able size. This is at first irregular and changes shape with the 
slow movements of the intersporangial protoplasm ; then it be- 
comes spherical and ultimately disappears suddenly. The proto- 
plasm itself is at first coarsely granular and after the discharge 
of the vacuole it is almost homogeneous. About five minutes 
after the vacuole disappears, the first cleavage lines of the spore- 
origins become visible and the protoplasm contracts slightly so 
as to leave a clear space just inside the wall. Soon after, dis- 
charge occurs, in the manner so often described for Phytophthora, 
the spores being fully demarcated and provided with cilia before 
they emerge to the outside.” “ The zoospores are more or less 
bean-shaped, one of the longer sides being convex and the other 
concave or plane. Each contains a small pulsating vacuole and 
two cilia arise near together from the concave or plane side, one 
projecting in front and the other behind while swimming. After 
swimming for some time they come to rest, round off, lose the 
cilia and become surrounded by a cellulose wall” (pp. 239-241). 
A cool temperature facilitates the discharge of the zoospores. 
The production of conidia does not appear to be in any way 
affected by light. 
On culture media chlamydospores are common. They vary in 
size from the diameter of the hypha to 30 fi, and are quite distinct 
in appearance from the oospores. As these also occur in P. 
Faberi and P. parasitica “ it is not impossible that the bodies de- 
scribed as parthenogenic oospores in several species are really 
chlamydospores.” 
Oospores were produced in various cultures. They are of the 
same type as is described for P. erythroseptica and P. parasitica. 
The oogonia measure 24-35^ and the oospores 20-28^. Their 
germination is unknown. 
