1003. Without some arrangement, the mind of man would be unequal to the task of acquiring even an imperfect knowledge of the various objects of nature. Accordingly, in every science, attempts have been made to classify the different objects that it embraces, and these attempts have been founded on various principles. Some have adopted artificial characters; others have endeavoured to detect the natural relations of the beings to be arranged, and thus to ascertain a connection by which the whole may be associated. 'It was formerly supposed,' Lindley observes, 'that the organs of fructification were more constant in their character, and less subject to variation, than any other part of the plant; and hence they were exclusively adopted as a means of classification. But modern investigations have shown that characters drawn from the mode in which plants grow, and from certain anatomical peculiarities, are of much higher value; so that the organs of fructification are now chiefly employed for the distinction of genera, or of orders and tribes. And, even in these minor groups, the organs of vegetation are frequently of high importance.' (Lindl. Introd., 1st ed., p. 308.)
