i 76 Bailey . — Puccinia malvacearnm and the Mycoplasm Theory . 
group ‘ A * one showed slight infection of the mature leaves and the other 
one showed a few pustules only. The plant in group ‘ C 5 previously 
recorded as slightly infected now showed a degree of infection correspond- 
ing to rather heavy ‘secondary infection’ in Eriksson’s description. One 
of the plants in group ‘ B ’ and one of the isolated plants referred to in the 
original description under the letter ‘ D ’ now showed one or two pustules 
on middle-aged vigorous leaves. The above account summarizes the 
appearance of these plants on the dates given : seen from day to day the 
impression was even more forcibly conveyed that this was a case of disease 
spreading from one plant to another by means of a normal process of 
infection, either from the plants originally recorded as diseased, or from 
others in the vicinity, which had been overlooked. 
The transition in the case of the two heavily infected plants in group 
‘A’ from a state of moderate infection of ‘secondary’ type to that 
resembling very heavy ‘ primary infection ’ was rapid, but showed all inter- 
mediate stages. All these plants arose from perennial root stocks, and in 
the case of group ‘ A ’ they grew in a yard which was known to have con- 
tained heavily diseased plants of Malva sylvestris for several years 
previously. 
3. Sudden appearance of disease in bidk in places far removed from 
outside sources of infection . The facts given by Eriksson are remarkable, 
but the observations just recorded above show that in cases of ‘ normal * 
infection the infective material can be and often is carried long distances, 
and that the appearance of the first few isolated pustules is followed very 
rapidly by conditions of intense infection. Moreover, these records show 
the existence of a relatively large amount of infective material, in this 
country at least, at an early period in the season of growth. 
4. Non-viability of teleutospores which have passed through the winter 
withoiit germinating . It is an established fact that the vast majority of 
over-wintered spores of this fungus lose their power of germination. 
Eriksson quotes the work of previous investigators in support of this, and 
records a few cases in which he himself tried to germinate such spores, but 
without success. The experience of the present author points in the same 
direction. Eriksson, however, quotes Fischer as finding germinable 
teleutospores as far through the winter as January 31, and Taubenhaus 1 in 
America has shown that such spores can be germinated as late as April in 
the year following their formation. The last named points out that the 
older the spore is the longer it takes to germinate, and suggests that 
previous negative results might likely be explained on the assumption 
that the teleutospores had not been left long enough in the drops of 
water. 
That this delayed germination takes place but sparingly in nature is to 
1 Taubenhaus:- Puccinia maivaccantm, Mont. Phytopathology, vol. i, No. 3, 
