IlfTRODtrCTIOlT. 31 



Suppose the plant to be a Violet. Although the anthers are united in a 

 ring, the flowers are quite separate, each with its own calyx, and we are 

 referred by the second alternative to the third bracket, the double perianth 

 refers us to the fifth, the free ovai-y to the sixth, the single ovaiy to the 

 seventh, the irregular corolla to the fortieth, the spur to one of the petals 

 to the forty-first, the five stamens to the forty-second, under which the five 

 sepals and petals indicate at once the genus Violet. We then compare our 

 plant with the description of the genus in the Flora, before we proceed 

 to ascertain the species. In making use of these descriptions, the beginner 

 must be careful not to be misled by the popular meaning of terms to which 

 a technical sense has been given by botanists, and in aU cases of doubt he 

 should refer to the definitions through the Index of Terms. 



After a little habit, this mechanical process will be much abridged. The 

 great divisions of the general anajytical table will be at once recognized, and 

 very soon the large Orders and genera will become so famihar, that in most 

 cases the amateurs will only have to commence with them. Yet in all cases 

 of doubt and hesitation, wherever the plant does not agree perfectly with 

 the generic character and description, he must revert to the beginning, and 

 carefully go through every step of the investigation before he can be satisfied. 



And notwithstanding the care that has been bestowed on the framing of 

 the analytical keys of the present work, and the number of cases in which 

 they have been verified, specimen in hand, through every stage, it cannot 

 be hoped that they have been rendered so precise as to preclude doubt. 

 The beginner especially wiU often be at a loss as to which alternative agrees 

 the best with the plant he is examining, and one false step may lead him 

 far away from the object he is seeking. But let him not be discouraged ; 

 perseverance, a fresh examination of his specimen, or of others of the same 

 plant, a critical consideration of the meaning of every expression in the 

 characters given, may lead him to detect some minute point overlooked or 

 mistaken, and put him in the right way. Even experienced botanists, pro- 

 vided with the most detailed descriptions in systematic works of the highest 

 repute, are occasionally led into false determinations. Species vary within 

 limits which it is often very difficult to express in words. In making an 

 analytical table, it often proves impossible so to divide the genera or species 

 which have to come under one bracket, as that each alternative must ex- 

 clude aU that come under the other one. In such cases it has been found 

 expedient to make both alternatives lead to the doubtful genus or species, 

 although for brevity's sake this has been avoided when not thought abso- 

 lutely necessary. 



It may also happen that the specimen gathered may present some occa- 

 sional or accidental anomaUes peculiar to that single one, or to a very few 

 individuals, which may prevent the species from being at once recognized 

 by its technical characters. It may be useful here to point out a few of 

 these anomalies which the botanist may be most likely to meet with. For 

 this purpose we may divide them in two classes, according as these aberra- 

 tions or anomahes may be attributed to some general climatological or other 

 influences, or as they are, as far as our knowledge goes, purely accidental. 



1. Aberrations from the ordinary type or appearance of a species, for 

 which some general cause may be assigned. 



A bright hght and open situation, particularly at considerable elevations 

 above the sea, or at high latitudes, without too much wet or drought, tends 

 to increase the size and heighten the colour of flowers, in proportion to the 

 stature and fohage of the plant. 



