THALLOGENS. 263 
This, the latest and most important form, consists in globulous 
conceptacles, sessile, at first colourless, then yellowish brown, 
and finally black and more or less spotted, which bear, like the 
Fig. 330.—Reproductive Organs of Erisyphus (Pycnides). 
two first sets of organs, certain filaments of the mycelium. They 
are all accompanied at maturity with a variable number of filiform 
appendages, whose form, dimensions, and position vary with the 
Fig. 331.—Third kind of Reproductive Organ of Erisyphus (Conceptacies). 
Spores under consideration (Fig. 331). They are simple or 
branching, and frequently terminate in arms divided into pairs. 
In the bosom of the conceptacles are found sacs or theca, variable 
also in number, generally ovoid, attached by a short claw to the 
base of the conceptacle. The number of spores, which are constant 
to each species, vary from two to eight. The conceptacles open 
“regularly in order to permit the theca or spores to issue. 
