148 Philippine Journal of Science 1919 
corn. Swarm spores were readily obtained in Van Tieghem 
cells by growing the organism on very dilute agar or in hang- 
ing drops of water placed on sterile cover slips. Just before 
formation, there appears a rearrangement of the protoplas- 
mic granules. The swarm spores are then produced within 
the sporangium. The papilla finally breaks off, and the spores 
escape. No vesicle foimiation has been observed. The spores 
near the opening escape one by one. Each rests for the period 
of a moment on the outside, and then swims off rapidly. As 
soon as a few spores have escaped, those remaining swim about 
actively within the sporangium and escape one at a time. The 
swarm spores are kidney-shaped. They swim about for a time 
by means of two flagella and then come to rest. At this stage 
they become spherical and may germinate after a few hours by 
the production of a germ tube. 
CHLAMYDOSPORES 
Chlamydospores are produced directly from the mycelium, 
usually terminally, but sometimes intercalarily. They are spher- 
ical, granular like the conidia, but with a slightly deeper yellow 
shade. In pure cultures they are produced in great abundance 
on oat meal or potato agar. 
Measurements of chlamydospores. — The size of the chlamy- 
dospores is one of the criteria by which the species are separated. 
Two hundred measurements were made of the spores from cul- 
tures 3 to 10 days old on oat meal agar, and one hundred mea- 
surements of spores from cultures 6 and 7 days old on macerated 
corn. A summary of these measurements, grouped in classes, 
appears in Table VII. 
The chlamydospores vary in diameter from 15.5 to 57.49 mi- 
crons, the largest number falling in class 39.5 to 41.49 microns. 
The mean diameter is, therefore, more than 35 microns, being 
approxim.ately 39 microns. These measurements correspond 
closely with those for Phytophthora faberi Maubl., found in 
the classification prepared by Rosenbaum. (lO) There was little 
or no difference in size between the chlamydospores produced 
by the fungus growing on oat meal agar and those produced 
on macerated com. 
Germination of chlamydospores. — In Van Tieghem cells pre- 
pared with hanging drops of distilled water, corn meal extract, 
pure agar, or potato agar, direct germination will take place 
within twenty-four hours. From one to twelve germ tubes may 
arise from one spore. 
