About ten years ago I purchased from Messrs. Ellwakger & Barry, of Mt. Hope, Rochester, N. Y., a lot of Plum trees of the different leading varieties, planted, cultivated, and drove them right up into bearing, and for the last four years have had full crops of truly noble and luscious specimens of each, and, what is highly gratifying, the trees are entirely free from black gum, or black knot, and are kept so by freeing the branches from all diseased or rotten fruit as soon as it appears.

Strict and close observation for many years past, and the examination of branches upon which the Plum has undergone the process of decomposition in the warm months of August and September, has served to settle the question with me beyond a doubt I will here refer the reader to trees in his own grounds, say Washington, Huling's Superb, and White Magnum Bonurn, Take your knife, go to any of these that may have dried Plums on; take them off, examine and cut, and in many cases you will find a mortal wound, black, cankered, bark bursted, swollen, and perforated full of holes. These were made by the same worms and insects that were feeding on the decaying fruit, after which fails they find nearly the same food in the well-saturated and decom. posed bark, immediately under the rotten fruit, which they feed upon for a certain time and then pas3 away. They were attracted hither for food only, and not to perpetuate their progeny. They are not the real first cause of the disease, as some have it, yet they hasten the complaint by eating holes in the bark through which the deadly and poisonous gasses and juices enter, and so get into the circulation and is carried to the extremity of said branch, and if a scion is cut from such, the young tree will show it even in the nursery row.

The wont cases will be found where the Plum rots on the top, or upper side, of a horizontal branch about an inch or so in diameter, yet I have found even spurs and the smallest branches badly affected by the same, and many killed the first summer by the deadly juices of the affected fruit.

All who grow Plums well know that many varieties bear in clusters, and also know that when a cluster is attacked with the rot, if the diseased Plum is not timely removed the whole cluster will be lost (particularly so in the finest sorts) in a few days. Just so, on the other hand, if the same poisons enter the circulation and get into the body and very heart of a tree, death is certain, though, unlike the fruit, it will take years, instead of days, to accomplish it.

I look upon the above as the true cause of black knot, and as destructive to the Plum as the bite of a road dog, or as the juices from the flesh of a human being in a state of decomposition, would be to ourselves if applied in a similar manner. The subject is worthy of consideration. Will some able pen take it up! Wm. H. Read. - Port Dalhousie, C. W.