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Publications of Interest to Agriculturists. 
3. If the disorder has become chronic, it would be well to cut 
down an infected tree whose propinquity to healthy trees would be 
dangerous, or to cut away all diseased branches from those not 
infected, and to graft them. 
4. Some varieties are not so liable to canker as others ; it is 
therefore desirable to choose those for planting which appear from 
examination of the orchards of the district to be free. 
5. All cankered wood must be cut away every year, as it serves 
as a harbour for the Nectria, which can live as a saprophyte. 
It is recommended to spray cankered fruit trees with sulphate 
of iron and sulphuric acid, according to the subjoined formula : — 
Sulphate of iron, 110 lb. 
Sulphuric acid (poured on the sulphate of iron), If pints. 
Boiling water, 22 gallons. 
When cold this may be applied with the Eclair machine or with 
a garden engine. It is considered that the application of bouillie 
bordelaise would also be effectual in checking the progress of Nectria 
ditissima. 
The action of the woolly aphis [Aphis lanigera ) upon apple trees 
is well ‘ known. In some seasons and to some varieties of apple 
trees this insect does considerable harm by sucking the juices from 
the younger branches and twigs, and making nodules or excrescences 
upon them. But M. Dangeard has discovered that a fungus follows 
in the wake of the aphides and completes their work of destruction. 
When by reason of local hypertrophy of the nodules, or swellings 
raised by the irritation of the insects, there is a rent made in the 
bark, and the tissues of the branch are laid bare, the fungus appears 
immediately. M. Dangeard saw this in a nursery in which the trees 
were greatly injured by the united attack of insects and fungus. 
The latter especially penetrated into the tissues of the young 
branches, disorganising them and eventually killing them. A 
figure is given illustrating the action of the fungus, showing the 
parenchyma of the nodules penetrated by its mycelial threads. An 
elaborate description of the fungus elucidated by figures of many 
of its stages seems to indicate that it is a species of Cladosporium. 
This is the first time, M. Dangeard observes, that the special 
action of this parasitic fungus has been noticed. When the woolly 
aphis is at work alone the vital parts of the infested branches may 
recover their normal functions : the tree is less vigorous, it is de- 
formed, but in general its branches do not die. If the fungus is de- 
veloped the vitality of the branches is destroyed and they die above 
the injury. M. Dangeard terms this le chancre noduleux (the canker 
of the nodules), and is of opinion that it does not act independently 
of the woolly aphis, therefore that steps should be taken to get rid 
of the insect by syringing the trees with a mixture of petroleum and 
soft soap. He advises that all branches and twigs infected by the 
fungus should be cut off and burnt. 
The blackening of the leaves of apple and pear trees caused by 
Fusicladium [Cladosporium) dendriticum is treated under the head of 
