Certain insects also prove injurious in the nursery, among these the most numerous are the _aphides_, which are found upon the roots of some fruit trees, especially the apple. Others of this disagreeable insect appear upon the foliage, among these one of the most disgusting is the one which causes the black curl, on young cherry trees. The pear tree slug, (_Selandria cerasi_), destroys the foliage of many young trees in the nursery; caterpillars also do their share of mischief. A serious trouble in old nursery grounds, especially where manure is used, is the grub of the May beetles, of which there are several species. These grubs are whitish, nearly as thick as the little finger, with a brownish head. They cut off the young nursery trees at three or four inches below the surface. We have seen two-year old stocks cut in this manner, and the work of destruction was so complete, that the proprietor of the nursery was a long time in attributing it to such an apparently inadequate cause as this sluggish, soft-bodied grub. All of these, with other insects injurious to fruit, will be considered in their appropriate place. FOOTNOTES: [12] The Plant, a Biography: M.J. Schleiden, p. 68. [13] Because it had no root, it withered away. Mat. 13, 6. [14] Du Breuil, Culture of Fruit Trees; English Translation. [15] A.R. Whitney, Franklin Grove Nurseries, Lee Co., Ill. CHAPTER IV. DWARFING. DEFINITION OF. OBJECTS. EARLY FRUITAGE. DEFINITION OF TERMS. DWARFING STOCKS. OTHER MEANS OF DWARFING. DWARFS AND STANDARDS. PYRAMIDS OR CONICAL. ESPALIERS. LAYING BARE THE MAIN ROOTS IN SUMMER, TO DIMINISH THE VIGOR OF THE TREES. REMOVING A PORTION OF THEM. ROOT-PRUNING. TRANSPLANTING. EUROPEAN ESPALIERS AND WALL FRUITS. DU BREUIL'S CORDONS. CROWDING, AS A MEANS OF DWARFING. PINCHING, TWISTING, AND FRACTURE. FIELD'S PEAR HEDGES. OUR CLIMATE DOES NOT REQUIRE THESE MEANS OF TORTURE. FACILITY OF PROTECTION MAY RENDER THEM DESIRABLE. GENERAL INTRODUCTION OF QUINCE-DWARFED PEARS IN THIS COUNTRY. MANY FAILURES. SUCCESS DEPENDS UPON CARE. FRENCH SUCCESS. CHINESE. UNCONGENIAL STOCKS. IMPERFECT UNION. PINCHING. HIGHEST PERFECTION OF THE ART OF HORTICULTURE. EQUALIZE THE FLOW OF SAP. NATURALLY FLOWS TO HIGHER PARTS AT EXPENSE OF LOWER, MAY BE REGULATED BY TRIMMING. BY DISBUDDING. BENDING DOWN. PINCHING THE STRONGER, AND ENCOURAGING THE WEAKER. ILLUSTRATION IN THE STRAWBERRY. DWARFING THE APPLE. PARADISE STOCK. THE DOUCIN; UNFIT FOR ORCHARDS. ROOT-PRUNING. HOW IT OPERATES. TIME TO BEGIN. HOW TO BE PURSUED. SEASON FOR. EXPENSE. ROOT-PRUNING PLOW.