INSECT AND OTHER PLANT ENEMIES. 



67 



Martagon. Each plant therefore has two names, 

 one generic and one specific. The generic name 

 is analogous to a family surname, the specific 

 name corresponds to the baptismal name. The 

 analogy is not perfect, for in the case of human 

 beings we give a distinct name to each individual, 

 whereas in plants we do not name individuals, 

 but begin our nomenclature with the species. 

 It is customary in botanical treatises to add to 

 the name of the plant that of the author who 

 described it, thus, Lilium candidum, Linn., indi- 

 cating that it was Linnaeus who described or 

 classified the plant. In detailed monographs 

 the work in which he described it, the page, the 

 date of publication, would all be mentioned, 

 together with any synonyms the plant may have ; 

 but these are only requisite in a monograph or 

 book of reference. 



AVhen the same plant has, as often happens, 

 been described under two names, the rule is to 

 take the first correct name as the one to be 

 adopted, and to consider all others as synonyms, 

 to be disregarded in practice. For instance, 

 what we know as the Martagon Lily was once 

 considered (as by Ruppius and Salisbury) to 

 represent a distinct genus, i.e. Martagon, By 

 general consent, however, Martagon is not suffi- 

 ciently distinct to merit a separate generic ap- 

 pellation; and therefore the adopted name is 

 Lilium Martagon, Linn. The word being printed 

 Avith an initial capital at once informs the bot- 

 anist of the history of the plant. The principle 

 of nomenclature is to accept as correct the name 

 given by that botanist who was the first to 

 assign a plant to its right genus. As Linnaeus 

 was the first systematically to adopt the bi- 

 nominal system of nomenclature, and thus intro- 

 duce order into what was before confusion, so it 

 is customary now to take the Linnsean nomen- 

 clature, dating from 1753, as the conventional 

 starting-point, and to disregard any names that j 

 were applied before this date. 



In the preceding paragraphs an epitome only 

 of such portions of Botanical Science as are of 

 most interest to the gardener is attempted. 

 Those who desire to pursue the subject more 

 fully are referred to the following standard 

 books of reference : — 



A Student's Text- Book of Botany, by Sydney H. Vines, D.Sc. 



Swan Sonnenschein & Co., London. 

 A Popular Treatise on the Physiology of Plants for the Use of 



Gardeners, by Dr. Paul Sorauer; translated by F. E. Weiss, 



B.Sc. Longmans & Co., London. 

 The Treasury of Botany, 2 vols.; for the uses of plants and 



descriptions of the more important genera. Longmans & Co., 



London. 

 The Illustrated Dictionary of Gardening. Edited by George 



Nicholson. L. LJpcott Gill, London. 

 Cultivated Plants, their Propagation and Improvement, by F. 



W. Burbidge, ALA. W. Blackwood & Sons, London. 



Of elementary introductions there is a vast 

 number. Any of the following will be found 

 very useful : — 



An Introduction to Structural Botany, by Dr. H. Scott, Ph D. 

 Adam & Charles Black, London. 



The Elements of Botany, by Francis Darwin. Cambridge Uni- 

 versity Press. 



An Elementary Text- Book of Agricultural Botany, by M. 0. 

 Potter. Methuen & Co., London. 



A complete list of all flowering plants, from 

 the time of Linnaeus to the year 1885, is given 

 in the Index Kewensis, in four parts, and to 

 which a Supplement, bringing the work down 

 to 1895, is now in preparation. [m. t. M.] 



CHAPTER XI. 



INSECT AND OTHER PLANT ENEMIES. 



Bark Enemies — Bud and Flower Enemies — Fruit 

 and Seed Enemies — Leaf Enemies — Root Ene- 

 mies — Stem Borers. 



The subject of economic entomology is one 

 of ever-increasing importance. The number of 

 insects now known to be injurious to plants is 

 very large, and their rapid increase is often 

 alarming. Fortunately, however, the occur- 

 rence and depredations of many of them are 

 local, though a few are wide-spread and common 

 enemies. 



This chapter deals with all the more impor- 

 tant of those that infest gardens, orchards, fruit 

 and plant houses. The descriptions of them, 

 and the treatment recommended for their de- 

 struction or check, are necessarily brief. At 

 the end of each chapter, treating of any parti- 

 cular class of flower, fruit, or vegetable, the 

 insect or other pests that infest them are 

 mentioned, and thus form a sort of key to this 

 chapter. Should the insect be a scale upon the 

 trunk or branches of the apple-tree, it will be 

 found under " Bark Enemies ". If it is devour- 

 ing the leaves, or injuring them in any way, it 

 will be found under " Leaf Enemies " On the 

 other hand, should it be boring into the fruits 

 of an Apple or Pear tree, making them what is 

 termed worm-eaten, it will be found under 

 "Fruit and Seed Enemies"; and so on. all bein^ 

 arranged in alphabetical sequence. 



Bark Enemies. 



American Blight (ScJuzoneura lanigera). — 

 The wingless and viviparous females of this bark 

 louse are fat, sluggish, reddish-brown, changing 

 to a dull leaden colour, mealy on the back, and 



