DIRECTIONS TO THE UNPRACTISED STUDENT. 



The Student is supposed to have a general acquaintance with the rudiments 

 of Structural Botany, such as is readily to he acquired from the author's First 

 Lessons in Botany, or his Botanical Text-Book, or from any other similar trea- 

 tise. One of these will be needed for reference while using this Manual. The 

 former is much the simplest, and was expressly prepared for the beginner's use 

 To learn the meaning of all words he meets with, and which he does not precise 

 ly understand, he has only to refer, as occasion requires, to the Glossary or Dic- 

 tionary of Botanica" Terms appended to either of these books, especially to that 

 in the Lessons on Botany. 



To show the beginner how to proceed in using the Manual for the purpose of 

 ascertaining the name, and the place in the system, &c. of any of our wild plants, 

 we will take an example. Suppose him to make his first trial with the common 

 Spiderwort, which grows wild throughout the southern and western parts of our 

 country, is cultivated in most gardens, and hlooms the whole summer long. 



With a flowering specimen in hand, let the student turn to the following Arti- 

 ficial Key to the Natural Orders, p. xvii. Having flowers, it is evident the plant 

 belongs to the great series of Phcenogamoiis or Flowering Plants. To which of 

 its two classes is the first question. To answer this, let the student compare 

 the plant with the characters — that is, the enumeration of the principal distinc- 

 tions — of Class I. given on p. xviii.. and of Class II. on p. xxviii.h Without the 

 seeds, which may not he ripe, — and if they were it might require more skill 

 than could he expected of the beginner to dissect them, — we cannot directly 

 ascertain whether the embryo is monocotyledonous or dicotyledonous. But the 

 other characters are abundantly sufficient, and easy to verify. Take first the 

 stem; is it formed on the exogenous or endogenous plan 1 A slice across it 

 plainly shows, to the naked eye, or by the aid of a common magnifying-glass, 

 that there is no distinction of parts into pith, hark, and a ring of wood or woody 

 tissue between these two : hut the woody part of the stem is here represented by 

 separate bundles, or threads, whose cut ends, as seen in the cross-section in the 

 form of dots, are scattered throughout the whole diameter, — just as in a stalk 

 of Indian Corn, a rattan, or a Palm-stem, — leaving no central pith and showing 

 no tendency to form a ring or layer of wood. It is therefore endogenous. The 

 simple, parallel-veined leaves show the same thing, and so does the arrangement 

 of the flower with its parts in threes, — namely, three sepals, three petals, six 

 (twice 3) stamens; and even the pistil, if the ovary be cut across, is found to 

 have three cells. So the plant plainly belongs to Class II. Monocotyledonous or 

 Endogenous Plants. 



We have next to refer it to its proper Order under this Class, which is readily 

 done by following the successive subdivisions in the Artificial Key. The first 



