FLORA OF WASHINGTON AND VICINITY. 211 



requisite appliances, even wliere it is necessary to work at wilted and 

 compressed specimens. 



I need not say tliat a good microscope is indispensable, or repeat the 

 caution about supposing that a higli power is required. It is well to 

 have one with two or three lenses of different powers, and which may 

 be combined for very minute objects. What is known as the "Gray 

 microscope" is amply sufficient, and with certain improvements is about 

 all that is needed for systematic analysis. It should always be carried 

 in the pocket, separated, if need be, from the box that it comes in, and 

 which is used as a stand. Every botanist should have a pocket made 

 expressly for his glass, and should never be without it wherever he 

 may be. It is a great advantage to have a surface of some considerable 

 extent in front of the stand for tbe instrument and on a level with the 

 slide on which the object is to be i^laced. This is secured in the sim- 

 plest manner by laying down a book of the right thickness and using a 

 large piece of tin or sheet-iron in place of the glass slide usually j)ro- 

 vided. Upon this a whole plant of considerable size may be placed, 

 and the portion to be investigated brought under the glass. The steel 

 needles with handles, which usually accompany microscopes of this 

 class, are useful, but if broken or lost an excellent substitute is a thorn, 

 either from the cockspur thorn {Grata'gus Crus-galJi), or from the honey 

 locust {Gleditschia triacanthos). These wooden needles have the advan- 

 tage over steel ones that when wet they do not so iiersistently pick up 

 the small seeds, etc., which it is desired to put into position. 



A young botanist's struggles with botanical keys can only be sympa- 

 thized with ; they can scarcely be aided by any general directions, and 

 there is no more effectual drill than the persevering effort to identify, 

 by the aid of a kej", a plant to which he has no clew. It should be the 

 ambition of every such beginner to analyze in this manner all the jilants 

 of his local flora. The more aid he receives from those who already 

 know their names and tell them to him, the more superficial will his 

 knowledge of botany be. It is the duty of his teacher, if he has one, 

 to give such suggestions as will guide him over the worst obstacles and 

 prevent discouragement, but he should never be told what his plant is. 

 In finding out the name of a plant for himself he must necessarily learn 

 much of its nature, and this information he will never again take the 

 trouble to acquire after he has once come into possession of the object 

 sought, i. €., its name. When he has learned this he imagines that he 

 Jcnows what the.plant is, and yet he does not really know what it is until 



