_Characteristics._--The woody or spongy excrescences which appear on the vines, and which are known as black-knots, are really only a wart-like growth, the origin of which is entirely unknown. It is supposed that an insufficient outlet for the sap in the spring caused by too close pruning is the chief cause. Certainly closely pruned vines are more subject to the black-knot than long pruned vines, but on the other hand neglected vines which have had no cultivation, and which accordingly could hardly have had too rapid a flow of sap, suffer more than any others. The woody warts appear quite frequently on the ends of the spurs of the old wood, or on places of last year’s growth which have been wounded or injured in some way, but never on the green wood. They vary in size from that of a pea to that of lumps weighing several pounds. When present in small quantities, the warts cause no injury, but when they become larger the vines may even die. These black-knots always die with the year, and never survive to the next season. At the end of the season, they burst open and then often display black spores of fungi, which, however, are only parasitical growths on the already decayed wood, and not the cause of the disease. As I said, it is generally supposed that the flow of sap is during spring time so great that it ruptures the cells of the vine and causes the warts to form. Under the microscope, however, there are no such ruptured cells visible. It is more natural to suppose, that through the accumulation of sap an irritating poison is originated, which causes the warty growth to form in a manner similar to the formation of galls. On sandy soil the black-knot is the most common, probably on account of the earliness and the natural warmth of this kind of soil. _Remedies._--So far no decidedly successful remedy has been found. Some growers advise leaving plenty of spurs on the vine, so as to give a sufficient outlet to the sap, but it remains to be seen if this will mitigate the evil. If the black-knot should be very destructive, a cutting out of the same in summer time while they are forming would be beneficial. This could best be done in June and July. Mixtures of coal-oil and lime, etc., have been used during the winter after the vines were already pruned, but, as the black-knot is then already dead, no advantages can result from this remedy. GRASSHOPPERS. _General Notes._--While grasshoppers cannot be considered as a common pest in the vineyard, still they are at times greatly destructive. There has been during the last sixteen years two such invasions of grasshoppers in the California raisin districts. The grasshoppers are of many species, some seventeen kinds having been recognized one season. They all breed in the waste or unplowed ground outside the vineyard, and when full-grown invade the vines. This fact can be taken advantage of to destroy them.