INJURIOUS INSECTS OF 1904. 157 



qualities. The snow melting in the spring discloses their work to 

 the nurserymen, trees oftentimes being completely girdled. Even 

 a girdled tree will live the first season, the sap finding its way to 

 the top through ducts in the wood, but later it is sure to die unless 

 prompt measures are taken to save it. The only way to do this, 

 and it is well worth the time when the tree is a valuable one, is 

 bridge-grafting. Fig. 159 shows what this means, and illustrates 

 the process so clearly that there is hardly need of words. Girdled 

 trees, too small to bridge-graft, may be grafted in the ordinary way 

 below the injury. In bridge-grafting make three grafts rather 

 than two. If large trees are only partially girdled, bridge across 

 the injured place. The tree's own branches may be used for bridge- 

 grafting. In course of time the injury is obliterated by the growth 

 of the bridge grafts. Pressing down the snow and what is below 

 it around the tree with the feet is a help in that it makes it harder 

 for the animals to get at the trunk ; there is a solid barrier, as it 

 were, protecting it. 



Other remedial or preventive measures are as follows : Keep 

 ground clean of grass and weeds, so there is no place to harbor 

 mice ; dig straw away from trees for a short distance ; protect 

 trees with wire mosquito netting wrapped once around trunk, 

 about fourteen inches high, or with wood veneer, or with building 

 paper; bank with dirt before freezing weather six or eight inches 

 above surface. Mice may be poisoned with strychnine, using corn 

 meal mush or wheat or corn, scattered about bases of trees. 

 Poisoned wheat already prepared can be purchased in some places. 

 Cats are instrumental in keeping down field mice; some dogs 

 delight in hunting them, and hawks and owls reduce their num- 

 bers. Strychnine, as mentioned eleswhere, must be used with 

 caution, that live stock or poultry may not suffer. It should, of 

 course, be kept out of the reach of children. Cats eating mice or 

 gophers which have died from strychnine poisoning would prob- 

 ably suffer the same fate as the animals they fed upon. Skunks 

 are said to do us a good turn by eating field mice. 



Thirteen-lined Gopher or Striped Gopher: Corn soaked or 

 dusted with strychnine, placing a spoonful in each hole, is a good 

 remedy. Wheat, if used, or corn, should be soaked for twenty- 

 four hours in a solution containing strychnine, and where the 



