1 82 B alley . — Puccinict malvacearum and the Mycoplasm Theory . 
Table I ( continued ) 
Date. 
Plant No. 
Inoculation 
Number. 
Material used for 
Inoculation. 
Results. 
Nature. 
Condition. 
4 . 6 . 19 . 
5 
27 
sporidial germination 
good 
Failed. 
28 
oidial 
It 
11 
2 pustules on lower 
surface and several 
black flecks. 
29 
11 
91 
11 
1 pustule on lower 
surface. 
30 
n 
99 
11 
Failed. 
6 
3i 
sporidial 
91 
11 
11 
32 
n 
99 
y9 
Failed, but showed a 
few black flecks 
33 
19 
11 
11 
Failed. 
34 
oidial 
11 
19 
Failed, but con- 
siderable number of 
black flecks. 
35 
19 
79 
11 
2 pustules on lower 
surface, and con- 
siderable number of 
black flecks. 
36 
79 
17 
91 
2 pustules on lower 
surface and con- 
siderable number of 
black flecks. 
7 
37 
sporidial 
11 
11 
1 pustule on lower 
surface. Many black 
flecks. 
38 
19 
17 
11 
Failed, but many 
black flecks. 
39 
99 
11 
19 
Ditto. 
40 
oidial 
11 
17 
Ditto. 
4i 
91 
If 
11 
Ditto. 
42 
99 
19 
11 
1 pustule on lower 
surface. Many black 
flecks. 
The occurrence of the black flecks of dead tissue in the inoculated areas 
of the leaves is interesting as showing the local lethal effects that the spores 
are capable of producing. They may occur with either sort of spore, and 
may possibly be connected with the histological changes in the cells of the 
leaf, which Eriksson has described in cases of negative infection, and w r hich 
he regards as the visible signs of mycoplasmic entry. 
8. Cytological changes in case of ‘ negative ' infections . Eriksson 
describes certain changes in the protoplasm of some of the epidermal cells, 
which he considers are due to the penetration of the protoplasm of ‘ oidial* 
spores, lying outside, into the cavity of the epidermal cells in the form of 
mycoplasm. 
Eriksson himself states that the channels by which the mycoplasm 
enters are too fine to be seen, and also admits that cases, similar to that 
just described, also occur side by side with normal positive infections. 
In view of this and of the lack of circumstantial evidence, it would 
seem simpler to explain the changes he describes as local lethal effects due 
