194 PRINCIPLES OF BOTANY, ETC. 
In a genus which has many species, if I should 
characterize the first by the spike, the second by 
the leaves, the third by the stem, the fourth by the 
root, the fifth by the fruit, &c. no person with cer- 
fainty would know the plants. 
It is necessary to observe in the species of a genus, 
what parts afford the best characters, and if there 
are many, they must be pointed out, and the dif- 
ferences remarked, that there may be no uncer- 
tainty or mistake. 
§ 194, 
It is only at the time of flowering, or of ripening 
the fruit that characters should be taken. | 
No botanist can with certainty distinguish plants 
without flowers or fruit, otherwise he must by fre- 
quent practice have attained a facility in distinguish- 
ing them by their leaves. ‘Thus characters afforded 
by plants before the developement of the flower or 
the ripening of the fruit are of no use. 
§:295. 
The other charaeters by which species are ascer- 
tained must be learned by experience. It is further 
however to be remarked, that a description is to be 
made according to the rules of accurate terminology, 
in the following order ; first the root, then the stem, 
the leaves, the fulcra, and lastly, the inflorescence. 
In a description, the colour of the flower is likewise 
to be mentioned, but superfluous or unimportant 
circumstances are to be omitted; such as that the 
root 
