250 The Ottawa Naturalist. 



the woody tissue is all collected so as to form a layer between a centra] 

 cellular part, the pith, and an outer cellular part, the bark, the increase 

 in diameter being by the addition ol new layers of wood beneath the 

 bark. The former class of plants, which includes our grasses, sedges 

 and lilies, is called endogenous or "inside-growing;" while the latter, 

 which includes all our northern trees and shrubs and most of our 

 herbs, is known as exogenous or "outside-growing." In Canada, the 

 endogens are all herbs with the single exception of Smilax. but in warm 

 climates they are largely represented by the palms. It is not, how- 

 ever, only the manner of growth that separates these two great divisions 

 of flowering plants : marked distinctions exist in the seeds, flowers and 

 leaves. But I shall not weary you with these distinctions, nor by 

 describing the principles upon which the exogens are again subdivided 

 into polypetala.', gamopetalre, and apetala? ; neither will I inflict upon you 

 the method of applying the system of classification to the naming of 

 plants. All these you will find laid down in your structural botany 

 under the heading " How to study plants." This I will say, however, 

 that the analysis or naming of plants, tedious and difficult as it may at 

 first seem, soon becomes very easy. After a few analyses the primary 

 steps can be rapidly passed over, and I will guarantee that any one who 

 will conscientiously study out twenty to twenty-five go.)d examples will 

 afterwards experience little difficulty in naming most of our flowering 

 plants. Be not discouraged at the slow progress you will at first make ; 

 each successful analysis will facilitate the next, and very soon it will 

 become so that when you have worked out one species of a genus you 

 will be likely to know others when you see them, and even when plants 

 of a different genus of the same family are met with, you will, ere long, 

 generally be able to recognize their order at a glance from the family 

 likeness. A capital practice for the beginner is to work out a few 

 plants with whose names he is already familiar. Suoe-^s in these 

 attempts will naturally inspire confidence in the determination of plants 

 previously unknown. 



By his initial reading over of his text book the student has got some 

 knowledge of plants and plant-life, as well as an insight into the manner 

 in which their names are determined. He is like the race-horse to 



