A, a plant infected in various parts: a, an attack below ground at the point of budding; b, canker on the stem above ground; e, an attack on a branch; d, a branch which has collapsed through being girdled by canker,
B, the first appearance of canker on a stem or branch: e, canker.
C, a branch from which a canker patch has been cut clean off to sound bark: f, the wound, which has been dressed with Stockholm tar thinned to a paint-like consistency with paraffin oil.
D, the effect of cutting off a canker patch: g, growth of new bark at the circumference of tho wound.
E, tho Rev. H. B. Biron's mode of curing canker: h, canker on the stem at the collar of the plant; i and j, slit made vertically through and continued
above and below the canker; k, canker on a branch; l, slit made through the canker.
F, result of cutting through the canker patches: m, the slit, which has opened and fresh bark formed at the edges; n, point from which new roots are often emitted; o, a slit on a branch which has opened and fresh bark formed at the edges of the cut; p, a vigorous shoot which has pushed.