CHAPTER VI.—PHENOMENA OF GERMINATION, 345 
Coleosporium, Leptochrysomyxa, Chrysomyxa, Cronartium, Hemileia, and others, in 
which the teleutospores belong to the first category,—the megalogonidia or resting 
gonidia of Hypomyces and its allied forms, some spores of the Ustilagineae and 
some others. 
The period of rest in many of these cases is observed to last for a fixed time, 
and to coincide with certain periods of vegetation and seasons of the year. The 
teleutospores, for instance, of the Uredineae, the most frequent representative of 
which is Puccinia graminis, are dormant during the winter. The teleutospores of 
Puccinia ripen at the end of summer and during the autumn and germinate under 
favourable conditions in the following spring, and it is difficult to procure their 
germination before that time even under cultivation. This appears also to be the 
history of the oospores of the Peronosporeae which do not live in water, and of the 
resting-spores of Protomyces macrosporus and some species of Synchytrium, S. 
Anemones for instance and S. aureum, &c. (see page 167), which all ripen in the 
summer and do not germinate till the next spring, and in their case also it is found 
difficult to shorten the resting period in plants under cultivation. 
It is different, according to Woronin!, with the resting-spores of Tuburcinia 
Trientalis among the Ustilagineae and of Sorosporium Saponariae, which ripen in 
the course of the summer and are not capable of germination before the end of 
September of the same year. 
This coincidence with a fixed period of the year is at least not a general rule in 
the zygospores of the Zygomycetes, in the oospores of many Saprolegnieae® (the 
Pythieae), and in the resting-spores of Synchytrium Taraxaci, though it may occur 
in some cases (Sporodinia, Synchytrium). In the absence of this coincidence we 
can only speak of a necessary period of rest which lasts some weeks or months and 
varies in different species and individuals. 
We have no exact observations on the maximum of the resting time possible 
under favourable circumstances in the case of species which are not confined to fixed 
seasons of the year. It may extend to a year and probably may exceed a year 
in the spores of Pythium proliferum kept under water. Our knowledge of the 
Zygomycetes and Saprolegnieae would lead us to suspect that, when the conditions 
required for germination are excluded, the power of germination ceases at an 
earlier period in them than in the more hardy forms, which retain their vitality more 
than a year without being obliged to go through a period of rest. 
The forms in which the resting time coincides with fixed periods of the year 
appear as a rule not to retain their powers beyond the favourable time for 
germination which follows their maturity, or not to retain them long beyond that 
time. Teleutospores of Puccinia graminis which have lasted during the winter 
germinate with great readiness in the spring which succeeds their period of ripeness, 
more slowly and more infrequently during the following summer months, and I was 
unable to procure their germination after August or in the spring of the second year. 
It is the same with other allied species. Woronin failed to make the spores of 
Tuburcinia Trientalis germinate when they had remained without germinating from 

1 Beitr. V. See also before on page 180, 
? See De Bary, Beitr. IV. 
