. Biology; the story of living things. MAN'S CONQUEST OF NATURI<: 581 part of the United States, they have almost been exterminated. Even more serious is the more recent introduction of the Dutch elm tree disease, a wilt that was introduced in an importation of European elm logs shortly before 1930. At that time, this disease had been found in several localities extending as far west as Indiana and Ohio and as far south as Norfolk, Virginia, marking places where the infected logs had been shipped. It attacks the wood and is spread by the European bark beetle as well as by other means. A det
. Biology; the story of living things. MAN'S CONQUEST OF NATURI<: 581 part of the United States, they have almost been exterminated. Even more serious is the more recent introduction of the Dutch elm tree disease, a wilt that was introduced in an importation of European elm logs shortly before 1930. At that time, this disease had been found in several localities extending as far west as Indiana and Ohio and as far south as Norfolk, Virginia, marking places where the infected logs had been shipped. It attacks the wood and is spread by the European bark beetle as well as by other means. A determined campaign is now being waged to stamp out this disease, which, unless controlled, will doom our native elms to destruction as it has those of. USUAL inular \o -jJJ Dutch elm disease. Brood galleries of Scolylus muUisfriatus, an imported beetle. Europe in the past fifteen years. The latest estimate by Charles Lathrop Pack calls for the destruction of 25,000,000 trees in order to save the remaining elms on this continent. In view of a program of this magnitude it would seem impossible to save our elms, because of the difficulty in completely eliminating the fungus. The most important class of the fungi from the economic viewpoint are the Basidiomycetes, fungi that bear asexual spores on a charac- teristic structure called a hasidium. Among the worst pests of this kind are the corn smut, which causes the commonly seen smut balls in ears of corn, many different grain smuts, grain rusts, and one white pine blister rust, besides many fungus diseases of wood. In this class are also found the mushrooms, both edible and poisonous. If we add to the above list the poisonous plants of this country, such as loco-weed, jimson weed, poison ivy, poison oak, and poison sumac, we have a formidable list of plants contending with man for Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and app
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Keywords: ., bookauthorwalterherberteugeneb1867, bookcentury1900, bookpublish
