Bailey .—Puccinia malvacearum and the My coplasm Theory. 191 
also 18 plants of each of the two double pink varieties. These pots were 
kept in the same greenhouse as the globes. 
Two dozen plants of each of these three kinds were planted out at the 
same time in a garden half a mile distant. 
On May 1, 1914, each of the plants in the globes had from 7 to 10 
leaves, the largest of which measured 4J inches across and was borne on 
a stalk 10 inches long. The ‘ pot-controls ’ were somewhat smaller and bore 
only about six leaves apiece, and the plants which had been started in 
boxes were smaller still, owing to a period of overcrowding. 
At this date the plants in the globes were lighter in colour and their 
leaves were less rugose than those grown in the normal way, but they 
appeared to be more vigorous than the controls. 
At the end of June the difference in size between the ‘globe’ plants 
and the ‘ pot-controls ’ was even more striking, as will be seen in Fig. 2, 
which is drawn to scale from a photograph taken on that date. 
At this date no rust had appeared on any of the plants, including 
those which had been planted out. 
In the early part of July, during a sudden burst of sunshine on an 
otherwise cloudy day, most of the fully expanded leaves inside the globes 
were scorched by the sun. The worst affected of these subsequently died, 
and, dropping to the bottom of the globes, became infested with saprophytic 
moulds. 
These dead leaves were removed in order to keep down the saprophytic 
fungi, and in the course of this operation the globes had to be opened for 
a short time. 
At the end of August the growth of the plants in globes was still 
good compared with that of the four sorts of controls in pots in the same 
house, which had suffered a good deal from the attacks of red spider. 
All the plants inside the greenhouse still remained free from rust, 
despite the fact that the plants which had been set out in the open now 
showed a plentiful infection. These latter had all sent up flowering spikes, 
and the rust was distributed over all except the very youngest leaves, which 
were unaffected except in very rare instances. 
The pustules on the older leaves at the bottom of these plants were in 
a more advanced stage than those farther up, and were obviously the result 
of an earlier infection. 
The plants which had been started in boxes and subsequently potted 
up had made very poor progress, and on August 22 they were repotted and 
stood outside under a north wall. 
On September 5, ten months after the start of the experiment, the 
plants in the greenhouse still showed no sign of disease, though this was 
three months after the latest possible expectation on the Mycoplasm 
Hypothesis. 
O 
