56 ROSEBUD. 
in this example in which the leaves are in threes, the 
rule of alternation still holds good. Figure 9. is the 
stem of the Madder, with four leaves in a whorl, and 
each whorl will be found to alternate with the one 
above and the one below it. 
Thus we find, not only an alternate arrangement of 
leaves, but also an opposite position of these organs. 
This rule is well worthy of remark, as it is one by 
which the nature of other organs is determined. 
90. Next to the leaves we have noticed certain organs, 
which to an inattentive observer would scarcely be 
deemed to partake of the nature of leaves; namely, 
bracts: they are leaves diminished in size, and often 
altered in colour, and in some plants they pass by very 
slow gradations from the condition of leaves to that 
of bracts. There can be no doubt that the bract of 
the Arum Lily is a leafy organ, or that the small green 
parts surrounding the flowers of the Daisy, Sunflower, 
or Marigold are of the same nature. 
91. Let the bud of a Rose be examined just before 
it has commenced blowing ; (pl. 19. f. 1.), in this, five 
sepals will be found enclosing the petals, and one of 
them will be seen to be outermost to all the others, and 
to possess several small leafy appendages on its margins 
and one at its apex, (f. 1. s.): these represent the 
diminished leaflets of a Rose leaf. If this sepal be 
compared with the two next outermost (f. 2.) it will be 
found that these appendages are fewer as the sepals 
are placed nearer to the petals: so that the two inner- 
most (f. 8.), or those which are covered in the bud by 
the three exterior, are provided with only one little 
