PUCCINIA POARUM 45 
Eriksson’s startling hypothesis can be accepted in regard to 
such ~ fungi as the Uredinales. 
The futility of Eriksson’s mode of argument is seen in his 
suggestion (1908) that “other diseases such as the American 
Gooseberry Mildew can live within the infected shoots in a 
form scarcely visible to our eyes.” But direct evidence against 
the Mycoplasm Theory is accumulating. Jaczewski (1910) 
grew seeds obtained from many much-rusted plants, but he 
found that, when they were sown under glass and protected 
with adequate care from all outside infection, they all produced 
rust-free plants. Bolley, Linhart, Zukal and Klebahn had 
similar experiences. Zach (1910) on investigating leaves and 
culms of Rye, infected with P. graminis and P. glumarum, 
found on the outskirts of the infection-patches all the states 
described by Eriksson, but he proved that in all of them fungal 
hyphe were present. In fact, Eriksson himself saw and repre- 
sented these hyphe, but calls them “radialen Strange ” of his 
supposititious “ Nucleoli,” the said “ Nucleoli” being merely the 
deformed remains of the nucleus of the attacked cell. As 
Marshall Ward (1905) remarked, Eriksson merely inverts all 
the stages of a fungus attack on a cell, and supposes the last 
state to be the first. This error and a misinterpretation of 
the microscopic appearances account for the whole wearisome 
persistence in an inherently improbable hypothesis. 
Puccinia Poarum. 
THE CoLTsFooT AND MEapow Grass Rwst. 
This species is economically of no importance; its spermo- 
gones and ecidia occur on the common Coltsfoot (T'ussilago 
Furfara), and its uredo- and teleutospore stages on species of 
Poa, to which however they do little harm. Here, again, the 
1 This does not accord with Eriksson’s experience; but then on some of his 
“protected” plants aphides also made their appearance, yet this does not seem 
to have suggested to him that the zooplasm of the aphides must also have been 
latent in the seed! If the aphides got in, so would fungus spores, since it has 
been proved (Butler, 1905) that uredospores are carried by them and other. 
insects. 
