OF THE STAMENS. 



57 



160 162 



Fig. 160. Frankenia, showing tlie five stamens (around the one style, which has 

 three stigmas at top). 



Fig. 161. Stamen (adnate) of Morning-glory. 



Fig. 162. Same, enlarged, w'ith pollen-grains discharged: _/, filament; a, anther, 

 — two-lobed ; c, top of conuectile. 



Fig. 163. Buttercup. Fig. 164. Same, cut across. 



Fig. 165. Iris, cut across (extrorse). 



Fig. 166. Amaryllis, — versatile. Figs. 167, 168. Larkspur, — innate. 



103. But dehiscence takes j)lace very variously. When all 

 regular, it is a chink running lengthwise along the outer edge, 

 as you see in this stamen of a Buttercup (Fig. 163). Buf 

 here, in this stamen of Iris (Fig. 165), it appears on the back 

 of the anther (looking towards the petals), and we say that 

 the anthers are extroTse.^ that is, turned outwards. A term 

 of opposite meaning is introrse^ denoting that the lines of 

 dehiscence turn inwards towards the pistil, or at least do not 

 turn outwards. For example, the anthers of the Yiolet 

 (Fig. 173). 



101. Moreover, other modes of dehiscence besides chinks 

 are occasionally found. The anthers of Berberis, Sassafras, 

 &c. (see Figs. 171, 172), open by lids hinged at the top. The 



103. When is tlic antlier said to be extrorse ? introrse ? 



104. Can you distinguisli tlie opercular and porous dehiscence? 



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