LESSON 30.] 



HOW TO STUDY PLANTS. 



183 



528. We should now look at the flower more particularly, so 

 as to make out its general plan of structure, which we shall need 

 to know all about as we go 



on. We observe that it has 

 a calyx of five sepals, though 

 these are apt to fall soon 

 after the blossom opens ; that 

 the five petals are borne on 

 the receptacle (or common 

 axis of the flower) just above 

 the sepals and alternate with them ; that there are next borne, a 

 little higher up on the receptacle, an indefinite number of stamens ; 

 and, lastly, covering the summit or centre of the receptacle, an in- 

 definite number of pistils. 

 A good view of the whole 

 is to he had by cutting the 

 flower directly through the 

 middle, from top to bottom 

 (Fig. 358). If this be done 

 with a sharp knife, some of the pistils will lie neatly divided, or may 

 be so by a second slicing. Each pistil, we see, is a closed ovary, 

 containing a single ovule (Fig- 359) ascending from near the base 

 of the ceil, and is tipped with a very short broad style, which has 

 the stigma running down the whole length of its inner edge. The 

 ovary is little changed as it ripens into the sort of fruit termed an 

 akene (Fig. 360) ; the ovule becoming the seed and fitting the cell 

 (Fig. 361). Reverting to the key, on p. ix, we find that the series 

 to which our plant belongs has two classes, one with " pistil a closed 

 ovary containing the ovules"; the other (p. xvi.) with "ovules 

 naked upon a scale or bract," etc. The latter is nearly restricted 

 to the Pine Family. The examination already had makes it quite 

 clear that our plant belongs to the first class, ANGIOSPEIIMJE. 



529. This class is divided into two subclasses, those with "leaves 

 netted-veined ; flowers usually 4 or 5-merous," to which might 

 be added the dicotyledonous embryo, but that in the present case is 

 beyond the young student's powers, even if the fruit were at hand ; 



FIG. 358. A flower of a Buttercup (Ranunculus bulbosus) cut through from top to bottom, 

 and enlarged. 



FIG 359. A pistil taken from a Buttercup (Ranunculus bulbosus), and more magnified ; 

 its ovary cut through lengthwise, showing the ovule. 360. One of its pistils when ripened 

 into a fruit (acttenium or akene). 361. The same, cut through, to show the seed in it. 



