Page:Popular Science Monthly Volume 88.djvu/83

Popular Science Monthly

HE startling operations performed upon human bodies by advanced surgical methods find their counterpart in tree surgery. How a pear tree was supplied with new roots after its own had been destroyed, is an example. The disease which required the drastic treatment of removing the roots of a well-grown tree is "pear blight," which can be eradicated only by cutting away all affected parts. So dangerous is this tree disease that even the knife which is used in cutting away the bark, wood or roots must be sterilized after each use, in order to prevent the contagion from spreading to sound parts of the tree.

Should the disease attack the roots, as in the instance shown in the photograph, it is necessary to supply nourishment to the tree by grafting to the trunk a number of healthy young "suckers." These are well rooted and are set into the ground about the diseased tree, while the upper ends are grafted upon the trunk, so as to carry the sap from the ground by healthy channels.

NE of the most interesting accidents that has ever come to the attention of zoologists is shown in the accompanying illustration. While lying in the tall grass near Fire Island, N. Y., waiting for game birds, Dr. A.L. Goodman, a New York physician, saw a fly perching upon a spear of grass near him, and entirely unafraid of the hunter, for it never moved. After watching the fly for nearly half an hour, Dr. Goodman's curiosity was so aroused that he got up and, upon examining the insect, found that the sharp point of the grass had pierced the fly's frail body.

The insect had evidently been flying against the wind, when a sudden gust blew it down against the blade of grass, which had swayed with the wind. Dr. Lutz, of the American Museum of Natural History, says that in the fifteen years that he has collected specimens he has never seen a similar accident, nor has he ever read of such an occurrence.

S a remedy for enlargement of the heart. Dr. Meyer Solis-Cohen hammers the spine with a rubber-tipped hammer. The tapping should be done on the protruding vertebra in the spine at the bottom of the neck, a little above the shoulderblade. It immediately livens the valves of the heart.