1 86 Bailey . — Puccinia malvacearum and the My coplasm Theory . 
expanded leaves was even greater than that shown in any of the photo- 
graphs in Eriksson’s paper of leaves suffering from a ‘ primary ’ outbreak of 
the disease. 
To return to the main experiment ; from the beginning of September 
onwards the controls in pots began to be much troubled by greenfly and 
later by red spider ( Tetr any chits ), wjiich much interfered with their 
growth, and necessitated treatment with paraffin wash. Notwithstanding 
this, two pustules were found on one leaf of one of these controls on October 
ii, and three weeks later another pot-control plant showed an equally light 
infection. 
The control plants in the outside border continued to show more and 
more rust as the season went on, but even at the time when they finally died 
down, none of the plants showed that dense infection which Eriksson has 
ascribed to * primary infection 
The plants in globes were observed up till the beginning of December, 
when growth had ceased altogether, the greenhouse not being heated. 
On December 4 each of these plants bore 8 to 9 leaves, of which the 
largest measured 3 inches across and was supported by a petiole 5 inches 
long. 
No trace of rust had appeared on any of these plants, despite the 
proved suitability of their environment and the fact that, on Eriksson’s 
expectation, the rust should have appeared, in bulk, by the end of September. 
It was found, however, on this date that a few patches of mould were 
growing on the oldest leaves, which had dried up and fallen away from the 
crown. 
These saprophytic fungi had doubtless made their way through the 
‘ sand-lock ’ at the bottom of the globe. 
From the middle of October to the beginning of December occasional 
Collembolae were seen in five of the globes. These live habitually in the 
soil and had doubtless worked their way up from below, and would be the 
means of introducing spores of saprophytic fungi. 
During the whole of the experiment all the plants growing in globes 
had remained perfectly healthy, with the exception of one, which was 
recorded on September 3 as showing a small black-coloured patch on one 
leaf, and which subsequently developed two similar black-coloured patches 
on one petiole. 
These affected leaves were removed through the top of the globe under 
sterile conditions, and were examined microscopically. No trace of rust 
could be found, and the black spots, which proved to be small areas of dead 
tissue, must be attributed to the action of Collembolae. 
No further action was taken with the globes until the following spring, 
when, growth restarting, the aeration of the globes was recommenced. 
At the end of April one leaf of one of the plants was inoculated with 
