LESSON 13.] TIIK UKLATIVF, rOSITION OF ITS PARTS. 



93 



Sec, also Iwivti their Howors construclccl on llic plan oC four as lo llie 

 calyx and coiolhi, but this munbcr is iiitirii'nd with in tlii' stamens, 

 either by the leaving out of two sta- 

 mens (which would eoiuplele two sets), 

 or in some other way. Next to five, \ 

 the most common number in flowers 

 is three. On this number the flowers 

 of Lily, Crocus, Iris, Spiderwort, and 

 Trillium (Fig. 189) are constructed. 

 In the Lily and Crocus the leaves of 

 the flower at first view appear to be 

 six in one set ; but the bud or just- 

 opening blossom plainly shows these to consist of an outer and an 

 inner circle, each of three parts, namely, of calyx and corolla, both of 

 the same bright color and delicate texture. In the Spiderwort and 

 TriUium (Fig. 189) the three outer 

 leaves, or sepals, are green, and dif- 

 ferent in texture from the three inner, 

 or the petals ; the stamens are six 

 (namely, two sets of three each), and 

 the pistils three, though partly grown 

 together into one mass. "" 



247. AUrriliUioil of Paris. The symmetry of the flower is likewise 

 shown in the arrangement or relative position of successive j)arts. 

 The rule is, that the parts of successive circles alternate with one 

 another. That is, the petals stand over the intervals between the 

 sepals ; the stamens, when of the same number, 

 ■ '^ c^W stand over the intervals between the petals; or 

 ^jj^ \\ when twice as many, as in the Trillium, the 

 ''^^ / li o"''^''" st't sdternates with the petals, and the 

 inner set, alteniating with the other, of course 

 stands bt'fore the petals ; and the pistils alter- 

 191 nate with these. This is shown in Fig. 181), 



and in the diagram, or cross-section of the same in the bud, Fig. 190. 

 And Fig. 191 is a similar diagram or ground-plan (in the form of a 



Fir.. 189. Fl..v\-cr of Trilli' 



iTliMii, nr ninlirool, Kprrail (Hit a littlo, and virwril froi 



abo 



FIG. 100. Diagrniii or cround-plan of ilic itainr, na it woiilil appcir in a cn>S!'-«iortion o( 

 ilio IiikI ; — llio parlH all In the nanio rrlativu |MiHiliiiii 



FlU. JUU Uiinjram, or ground pliin, ul lliu riax-tlowcr, Fig. 174. 



