ADDENDA 
Phytophthora erythroseptica, Pethybridge. 
Mycelium branched, becoming septate with age ; conidi a 
egg-shaped, produced sympodially, 20 X 32 p ; antheridia 
terminal, lateral or intercalary, subglobose or egg-shaped, 
penetrated at or near the base by the young oogonium, 
which passes through the antheridium and forms a pear- 
shaped body, which eventually contains a single globose 
oospore with a thick, brownish wall, 29—30 p diam. 
This parasite causes potato tubers to rot quickly. The 
cut surface of an infected tuber quickly turns pink, on 
exposure to the air, and later becomes almost black. The 
disease is popularly designated as Pink rot, and is the 
cause of serious injury to the potato in some parts of Ire¬ 
land. 
Judging from the account given, this appears to be a 
very remarkable fungus, but as there are many gaps to be 
hlled up by further research, the startling suggestions 
made may be to some extent modihed eventually. As to 
whether the conidia produce zoospores or a germ-tube 
on germination is not known, although it is stated that 
attempts were made to promote germination, by stimula¬ 
tion with oxygen gas. But it is the mode of development 
of an apparently sexually formed oospore, by the penetra¬ 
tion of the female organ through the substance of the male 
organ or antheridium, that renders this fungus, so far as 
its author can ascertain, quite unique amongst fungi. 
Long may it remain so. The cytological side of the question 
has not been studied, hence it is perhaps somewhat prema¬ 
ture on the part of the author to suggest the establishment 
of a new family for the inclusion of fungi presenting charac¬ 
ters, the significance of which is not understood. 
The paper dealing with this fungus is in The Scient. 
Proc. Roy. Dublin Soc., March, 1913. 
This species should follow Phytophthora infestans, De 
Bary. 
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