152 FUNGI. 
which as first take a lenticular form, and group themselves before 
the mouth of the parent cell in a globose mass (c.) Very soon, 
however, they begin to move, and then vibratile cilia show them- 
selves (d), and by means of these appendages the entire globule 
moves in an oscillating manner as one by one the zoospores 
disengage themselves, each becoming isolated and swimming 
freely in the surrounding fluid. The movement is precisely 
that of the zoospores of Algwx. 
The generation of the zoospores commences within from an 
hour and a half to three hours after the sowing of the conidia on 
water. From the oogonia, or resting spores, similar zoospores, 
but in greater number, are generated in the same manner, and 
their conduct after becoming free is identical. Their movements 
in the water usually last from two to three 
hours, then they abate, the cilia disappear, 
and the spore becomes immovable, takes a 
globose form, and covers itself with a 
membrane of cellulose. Afterwards the 
spore emits, from any point whatever of its 
surface, a thin, straight or flexuous tube, 
which attains a length of from two to ten 
times the diameter of the spore. The ex- 
tremity becomes clavate or swollen, after 
Fic. 92.—Resting spore the manner of a vesicle, which receives by 
of Cystopus ccndidus with degrees the whole of the protoplasm. 
a eel De Bary then proceeds to describe experi- 
ments which he had performed by watering growing plants 
with these zoospores, the result being that the germinating 
tubes did not penetrate the epidermis, but entered by the 
stomates, and there put forth an abundant mycelium which 
traversed the intercellular passages. Altogether the germina- 
tion of these conidia or zoospores offers so many differences 
from the ordinary germination of the Uredines, and is so like 
that which prevails in Peronospora, in addition to the fact of 
both genera producing winter spores or oogonia, that we cannot 
feel surprised that the learned mycologist who made these 
observations should claim for Cystopus an affinity with Perono- 
