On two species of Heterosporium particularly Heterosporium echinulatum $5 
from a leaf; but no discolouration was observed upon the leaf itself 
which seemed quite healthy. All those plants, however, inoculated with 
spores sown in 5 % glucose solution showed moulds upon their surfaces. 
One or two spots were noticed which extended from one side of the leaf 
to the other; this was in the case of Alternaria. Many of these mould 
spots were cut out, some being at once fixed in Juels solution, to be 
later on examined to ascertain if the fungus had penetrated the plant 
tissues; the rest were examined at once. In the latter case the mycelia 
could be removed like a sheet from the surface of the leaf. The mycelia 
of Heterosporium had produced numerous spores. No penetration of the 
Beta leaves could be made out in any case. 
Experiment II. 
* 
On 31 st October 1911 a further inoculation was made. Young Beta 
plants consisting of four or five foliage leaves were inoculated in the 
same manner as in Experiment I with spores of Heterosporium sp. and 
of Hormodendroti sp. The spores were suspended in (1) tap-water, and 
(2) 5 % glucose solution. In some cases the leaves were wounded with 
needles in other cases not. Eight pots were employed. 
Each pot as before contained five plants; one plant in each pot was 
inoculated with a suspension of spores in water, and one plant with a 
suspension of spores in 5% glucose solution. The remaining three plant 
in each pot were not treated in any way. 
In one pot the inoculated plants were first of all wounded by means 
of a needle. There were thus four pots in all; in two pots two plants 
were inoculated with Heterosporium\ in one of the two pots the leaves 
were wounded, in the other not. One of the plants in each of the two 
pots was inoculated with spores suspended in water, spores suspended in 
5% glucose solution were used in the other. In the other two pots the 
plants were treated in the same way but were inoculated with Hormo- 
dendron. 
Upon those plants inoculated with spores in water no fungus growth 
appeared at all; but upon those which were treated with spores suspended 
in glucose solution, one or two mould spots did make their appearance. 
In these cases the fungi were growing upon small portions of killed 
tissue at the edge of the wound. No penetration of healthy tissue was- 
found; and it was concluded that in these few cases the fungi were grow¬ 
ing as saprophytes upon tissue killed as the result of the wounding 
operation, and nourished by the remaining glucose. 
Experiment III. 
On 16 th January 1912 Beta- plants were again inoculated with 
spores of the Heterosporium- species originally found upon Beta. The 
plants used were those of the former experiment; they now consisted of 
from six to seven leaves about three to four inches in length, not coun¬ 
ting the petiole. 
One plant was chosen in one of the pots and three of its leaves 
were wounded, the mid-rib being torn across by means of a needle, the 
rest of the leaf was not touched. This plant was perfectly healthy. 
