792 THE TROPICAL AGEICULTUEIST. [June ?, 1902. 
"Bury all pods under at least two inches of boU 
with a eprinkiiug of lime. 
" C?(rc.— Gut out all diseased patches on baik or 
branches, removing also a wide marp;in— not lees than 
two inches — of opparenlly healthy bark, aud burn all 
the pieces removed. 
'■ If this method is too expensive or too drastic, 
shave lightly over the diseased areas and around thein, 
and burn the shaving!--. This latter treatment is not 
so effective as cutting out. Such work should be done 
vigorously in the dry weather, when the results are 
vastly better. 
"Keep aging of expert coolies continually on the 
look out for new canker patches, and liave these parts 
removed before they spread far or produce their spores. 
'• Notice any dead cacao trees or branches on neigh- 
bouring small holdings, and endeavour to get these 
removed and burnt. 
"These sanitary measures should be carried out on 
all estates, even where the canker is very rare, and 
thepersonal oversight of the superintendent seems to 
ba he only way to prevent small pa'ches of disease 
being missed in going round. It is much better to 
take a longer time in going round the estate and have 
the work thoroughly done than to cover large areas 
and overlook some canker." 
Another disease of cacao of which the nature is nrt 
yet exactly known, has been observed and investigatf d. 
This is a condition of small and unripe fruits, which 
is characterized by the unusal flexibility of the pods, 
giving them when handled the feeling as if made of 
indiarubber. Pods when in this condition are said to 
never attain full maturity, and, as a rule wither up 
and are of no use. I have not been able to find in any 
typical pods of this character any mycelium of a fungus 
or injury by insect and it is probable that this is 
another of the environmental diseases, the cause or 
causes of which are not yet apparent. That the 
fruits are fertilized seems proved, an examination of 
many showing a normal embryo. The loss by this 
going ofif " of a proportion of the pods is important. 
This condition must not be confused with the drying 
up of very small pods, which is reft-rred to later, and 
which at present seems to bs due to different 
causes. 
GREVILLEA DISEASE. 
A disease of GrevUlea rohiista very prevalent in 
certain districts is at present occupying my attention. 
This is a canker which, thou;5h it grows upon the roots 
of the Grevillea tree as well as tho stem, seems in 
mostcses to originate on the stem, usually near the 
base. The external signs ar-e a darkening of the baik 
accompanied, as a rule, with an exudaiion of gum at; 
various points. Some trees are being treated experi- 
mentally, and the fungus is being cultivatel, and its 
eSect on the tree examined, some healthy trees being 
inoculated for this purpose. A Circular will be issued 
and preventive measures recommended when the facts 
desired are obtained. 
Meanwhile it is important that a look out should be 
kept for this disease of a most valuable shado and 
limber tree. All specimens which seem to agree with 
this trhort description should be noted, and 1 will be 
glad to be informed of their existence and any facts 
bearing on the case. 
VINGER AND TOE DISEA'-E OF CABBAGES, &C. 
Passing from diseases of our extens-ively grov/n 
plants to those of others, the most important is 
I'liiimodioplioiu L'ra.ssico;, VVor., which has been found 
in more than one place on ctibbiises and turnips ; it is 
due to a fungus which attacks the roots aud sliows 
itself in maUormation of the root, lack of vigour, and sub- 
B( (jiiently in the death of the whole plant. This disease 
has been known in Europe for more than a hundied 
years, and in JOnglund is called "Finger and toe," 
" (JIub-root .Clulibiiif.', " and " Anbury." On the Conti- 
nent 1 he popular names alto have reference to the shnpe 
of the root , which lescniblcB fingers and toes. Thes 
jDalforiiialioiiH iiie due to the irritation or stimulus of a 
iungUB which bel'jrga to the group of Myxomjcetcs, or 
" Slime fungi," a most interes-ling gioup botanically 
but not so important ecoroniically, since hardly any 
of them pre parasitic, i.e.. ci-ease-producing. or other 
plants. This slime fungus is so called becaufe it has 
no outwaid shape, like ihe majority of the forgi, but 
consists of a mass of Plasmodium or jelly-like material 
which m?kes its way frr m cell to cell of the rcot and 
absoibs the contents of each 
After consuming all the food it can find it forms its 
spores — which aie the reproductive bodies and may be 
considered as feeds — and these can remain for seme 
time without sprcuting. In Europe they cirry the 
fungus over the winter and germinate in the spring. 
When conditions are favourable, these resting spores 
geiminateaud throw out a jelly-like material, which 
it comes in contact with the young root of a tabbage, 
turnip, or similar plant penetrates into it and produce 
the " fiiiger-and-toe " disease. 
There are two recognized methods of fighting this 
disease. The first is to starve out the fungus, and this 
is done by taking advantage of the fact that Plasmodio- 
phora Urasnicuj only grows on cruciferous plants, i.e., 
plants of the cabbage order. By not growing such 
plants as cabbage, kale, turnip, kohl-iabi, and 'ubsli- 
tuting crops of potato, lettuce, beans, peas, &c., the 
fungus cm obtain no food, and will eoi scquently in a 
few years be entirely exterminated. The otlipr one 
known is lime, end this is only a partial remedy. It 
has been found that acids favour the development of 
the " lioger-and-toe " fungus and alkalis retard it. 
Thus, a dressing of lime in a garden or field affected 
by this disease is of value, though not a certain pre- 
ventive. It is to be hoped that these measures, pre- 
ferably the former, may be taken wherever this evil 
is present in Ceylon, so that this disease may not get 
a foothold in this Island, such as it has in Europe, 
where it annually causes great losses to root crops 
and other plants. 
FUNGI CAUSING ROTTING OF TIMBER. 
Two other fungi have been studied both of economic 
interest, though not growing on living plants. 'Phe 
first is a species of Polyporeae growing upon beams 
used for building purposes and causing " dry-rot,' 
the name of which until the cultures have grown 
sufficiently to produce fruit cannot be given. Some 
experiments are being made with substances snited to 
preserve wood from the attacks of this fungus, and 
also with some different wo jds in use for bu'lding in 
Ceylon, as to their liability to attack. Some woods 
are by their structure less easily attacked by this fungus 
and it is well that the exact amount of immunity they 
possess should be known. 
FUNGUS ON RUBBER. 
Another is a fnngus which grows upon ssmples of 
rubber, those eXKUiined begin from Uevea UrasiUensis, 
Para rubber ; it was gi owing more abundantly upon 
those samples which had been precipitated with acetic 
acid, than on the untreated rubber, but this point will 
be experimented on. The fungus is a species of 
Syocephalis, and causes charoxteristic red markings 
in the sample, though not destroying its translucency. 
Whether the growth of this fungus on ths rubber 
affects the market price, I have yet to learn. 
OTHER DISEASES OF PLANTS. 
The following plants, in addition to those previously 
mentioned, have been i eceived as diseased ;« here the 
fungus caufiiig the disease or growing on the plant has 
been identified it is mentioned. In other cases the 
material did not afford means of identification : — 
Dillenia retusa, Thumb. Marasmius sarmentosus, Fr, 
Michelia Champaca, i. (Sapu;. Polyporus sangui- 
neirs, i'V. 
Garcinia Xanthochymns HJc. f. (Cochin Goraka.) 
Strigula Complanata, Fee. 
Oxalis corniculata, L. 
Mangifera indica, L. (Mango). Fusiciadinm, 
Crotolaria, sp. 
Desmodium cajansefolium, DC, Peronospora, sp, 
Phaseolus vulgaris, L, 
