The symptoms of pear-blight are so characteristic that the disease cannot be confounded with any other malady or condition of the tree. It appears earliest in the season on the blossoms causing blossom-blight. Attacked by blight, the blossoms wilt, and after the petals fall, fruit and spur show the characteristic blackening of the disease. Blossom-blight may escape the attention of the pear-grower, but twig-blight, a succeeding form of the disease, can escape no one who has the sense of sight. No other disease of the pear brings on such palpable destruction to the tree as twig-blight. No other disease causes such comfortless despair to the grower. Twig, branch, or tree, as the case may be, in all affected parts, turns black, the leaves droop, seeming to show the effects of fire. A marked symptom is, if there can be doubt of those given, that the blackened foliage clings most tenaciously to the dead branches. Twig-blight is the most common manifestation of the disease. Another form of the blight appears as a canker on the trunk and large branches--canker-blight or body-blight. These cankers are dark, smooth, and sunken, with definite margins marked by a crevasse in the winter; but as spring comes on the advancing margins become raised and more or less indefinite. Occasionally an opaque liquid oozes from lenticels newly attacked. On branches, the cankers usually surround a smaller offshoot, sucker, or spur. The disease spreads with great rapidity, by reason of which it is easily told from winter-killing. Injury from cold is also more general, and the foliage browns rather than blackens. Pear-blight is an American disease, the history of which was briefly given on page 51. Until recently it was confined to regions east of the Rocky Mountains, but since about 1900 it has been a virulent epidemic on the Pacific slope as well, and is now found from coast to coast wherever pears are grown in North America. It seems not to be found in the pear regions of other continents. It attacks the apple, quince, and other pomes as well as the pear, and plant pathologists declare it to be the most destructive disease attacking the pome-fruits. Trees in the nursery suffer as well as those in the orchard. Every variety of the pear bearing edible fruit is attacked. Fortunately, some sorts are more immune than others. Kieffer, Seckel, Winter Nelis, and Duchesse d'Angoulême are most resistant of standard varieties, while Bartlett, Clapp Favorite, and Flemish Beauty are little resistant.