131 
ly Healthy seedling cabbages planted. at Spin ering years | 
previously produced a os of diseased ca , became- 
Check’ plants from the ame batch of sedi €— in. sterilised mil, 
remained free from diseas 
A. me conducted i in a Sterilised Solution. of Stable Manure. 
2. ts of two flasks he infeeted by adding crushed 
tubercles of a diseased anaes root. Two per cent. of a saturate 
solution of potassium hydrate was added + to the contents’ of one flask, | 
and two per'cent. of commercial sulphurie acid to:the other. A young 
cabbage plant free from disease was then placed in each flash. At 
the end of two months the plant in the flask containing potassium 
hy as growing vigorously and perfectly free from di 
whereas the plant growing in the.solution containing sulphuric acid 
diseased, mu ie s0 ee check plants growing in 
infected soil free from for the e period of time. Similar 
experiments made Prem successive yenis always yielded the same 
result. 
3. Two young cabbage plants showing decided symptoms of disease 
were placed in flasks containing the same proportions of potassium 
hydrate and sulphuric acid respectively as in Experiment 2. At the 
_ 
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[1*] 
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et 
nodules present on the root at the commencement o 
having become effaced by subsequent growth. The plant growing in 
the solution containing sulphuric acid was badly diseased, 
Similar results were obtained in Experiments 2 and 3, when potas- 
sium hydrate was replaced by ammonium Ohi d and sulphuric acid 
by hydrochloric acid. 
Two diseased seedling cabl were placed in separate flasks of 
ed solution. The liquid "Se ie Mak wis saturated once a 
week with carbonic” dioxide, the contents of the second flask not 
g interfered with in any way. At the end of two months both 
plants had the bimi developed to the same extent, proving that 
carbonic acid is neutral as regards the development of P. Plasmodio- 
B. Experiments conducted with Sterilised Soil. 
5. Two pots of nil, sates by steam, were infected with the 
crushed roots of diseased cabbages. ."Lhe.soil.in one pot was mixed 
her wit i 
Le. a: 
the of two months the plant in the pot containing lime was 
tome tal whereas the plant in the soil bisio acid bone 
"bone 
ure aed ports el hi had a te Paii sahig eb in each. 
At t the end of two months the disease was more developed in both 
séedlings than at the time of a proving that the presence of 
lime will not arrest the disease when the mpm are once attacked. 
be apen ry. 
` The foregoing paor vions ds aede ie demonstrate the following 
pom ints — 
in. addi ition. to culti ivated plants, several. common weed 
PET to the order Crucifere are attacked by the Plasmodiophora, 
