170 Annual Report for 1905 of the Consulting Botanist. 
to swell. They had made a struggling growth, and were 
observed to be rotting rapidly. The leaves were small, black, 
and shrivelled ; they were found to contain numerous bacteria. 
No injury on the small roots was apparent externally. On 
cutting them they all showed a brownish discolouration 
under the skin, and a blackened ring about half an inch 
beneath the surface. These discoloured cells were, under the 
microscope, seen to be empty of food, but filled with numerous 
bacteria. One of the roots was carefully cleansed and then 
immersed for an hour in a 1 per cent, solution of corrosive 
sublimate. Sections from this, about half an inch thick, were 
cut with a sterilised knife and placed under conditions which 
prevented any infection. In a fortnight small colonies of 
bacteria of a greyish colour made their appearance, and these, 
removed by a sterilised needle to a slide, were found to be the 
same which had been taken from the diseased roots. Pure 
cultures will be used for infecting healthy roots in order to 
determine whether the disease is primarily due to this 
bacterium. The bacteria are from 1*5 to 2/x long, and from *8 
to 1 \x broad (see Fig. 2, C. At this stage of the inquiry the 
member could only be advised to lime his field and grow some 
other kind of crop. Appel has observed bacteria adhering to 
the seeds (fruits) of mangel that agree in form and dimension 
with those just described, and it may be that the infection has 
been due to the bacteria being sown with the seed. If this 
should be so, the immersion of the seed in a 2 per cent, solution 
of Copper sulphate would kill these organisms. 
A case of rust in wheat, and one of so-called clover sickness, 
caused by the fungus, Sclerotinia ciborioides Rehm, were 
reported on. 
An apple tree was examined, injured by the attack of 
Fusicladium dendriticum Wallr., and a peach tree affected by 
silver leaf. 
A larch plantation in Hampshire was visited to investigate 
the unhealthy condition of the trees. It covers the western 
side of a small hill, and extends into the small valley at the 
bottom for some fifteen yards. The trees were growing 
vigorously on the top of the hill, but had made little progress 
since planting in the valley. Holes were dug in the ground 
and the soil was found to be water-logged. Some of the 
unhealthy trees were lifted and they were found to have 
diseased roots. 
The valley had been drained, but portions of the drain had 
fallen in and it was useless. The limit of the diseased trees was 
distinctly marked. No affected trees were found towards the 
top of the hill, but only in the water-logged soil at the bottom. 
It was recommended that a deep open drain should be made, 
