94 
West. — On Stigeosporium Marattiacearum and 
Perhaps the most striking character which these genera share in 
common is the production of thick-walled ' resting * spores. About one-half 
of the species of Phytophthora hitherto described form thick- walled ‘ resting 5 
spores. Spores of this nature have been described for the following species 
of Phytophthora , viz. : 
Mentioned by : 
Dastur (19), Petch (36) 
Jones, Giddings, and Lutman (27), 
Dastur (19 A) 
Dastur (19) 
Butler and Kulkarni (12) 
Pethybridge (37) 
Pethybridge (37) 
Rorer (39). 
Species : 
P. Faberi , Maublanc 
P. inf e starts, de Bary 
P . parasitica, Dastur 
P. Colocasiae, Raciborski 
P. Nicotianae , de Haan 
P. Jatrophae , Jensen 
Cacao Phytophthora (P. omnivora ?) 
And it is not improbable that the parthenogenetic oospores, described 
by Coleman (17) for Phytophthora Theobromae , Coleman, are of a similar 
nature. 
The description and figures of the structure and development of the 
resting spores of Phytophthora infestans published by Jones, Giddings, and 
Lutman (1. c.). except for a few minor differences, could be applied equally 
well to the resting spores of the endophyte of these marattiacean roots. 
And the discovery of ramified haustoria in Phytophthora infestans by 
Delacroix (20, p. 361, Fig. 2) and by Dastur (19 A, p. 5) is also of interest. 
The chief points of difference between the two genera may be attributed 
to the peculiar habitat of our fungus, which no doubt has become associated 
with special adaptations, amongst which we find an almost complete 
suppression of certain reproductive bodies generally characteristic of the 
Peronosporae, namely, the sporangia, oogonia, and antheridia, the modifica- 
tion of the conidia, and a remarkable specialization of the vegetative parts. 
Since, however, we unfortunately have no available evidence regarding 
sexual reproductive bodies in this fungus, nothing precise can be stated as to 
its affinities, but the marked difference in habit between this fungus and 
Phytophthora is sufficient to make its inclusion in the latter genus unjusti- 
fiable. 
I therefore propose to establish a new genus, Stigeosporium} for its 
reception, and, since it is undoubtedly normally associated with roots of the 
Marattiaceae and, so far as is known, is confined to that habitat, I suggest for 
it the specific name Stigeosporium Marattiacearum . 
5. Geographical Distribution of the Fungus . 
This fungus has a remarkably extensive geographical distribution, the 
same species being found in the marattiacean Ferns occurring in such widely 
1 Or Stygeosporium. 
