114 



THE STAMENS. 



[lesson 17. 



29o. To discharge the pollen, the anther 0{)ens (or is dehiscent) 

 at maturity, commonly by a line along the whole 

 length of each cell, and which answers lo tlie 

 margin of the leaf (as in Fig. 231); but when 

 the anthers are extrorse, this line is often on the 

 outer face, and when introrse, on the inner face 

 of each cell. Sometimes the anther opens only 

 by a chink, hole, or pore at the top, as in the 

 2S5 23S Azalea, Pyrola or False Wintergreen (Fig. 235), 



Arc. ; and sometimes a part of the face separates as a sort of trap-door 

 (or valve), hinged at the top, and opening to allow the escape of the 

 pollen, as in the Sassafras, Spice-bush, and Barberry (Fig. 236). 

 Most anthers are really four-celled when young; 

 a slender partition running lengthwise through . 

 each cell and dividing it into two compartments, 

 one answering to the upper, and the other to the 

 lower, layer of the green pulp of the leaf. Oc- 

 casionally the anther becomes one-celled. This 

 takes i>lace mostly by conjiuence, that is, the two 

 cells running together into one, as they do 

 slightly in Pentstemon (Fig. 237) 

 and thoroughly in the Mallow Family (Fi 

 sometimes it occurs by the obliteration or disappear- 

 ance of one half of the anther, as in the Globe Ama- 

 ranth of the gardens (Fig. 239). 



296. The way in which a stamen is supposed to be 

 constructed out of a leaf, or rather on the plan of a 

 leaf, is shown in Fig. 240, an ideal figure, the lower 

 part representing a stamen with the top of its anther 

 cut away ; the upper, the corresponding upper part of 

 a leaf. — The use of the anther is to produce 

 297. Pollen. This is the powder, or fine dust, commonly of a yel- 

 low color, which fills the cells of the anther, and is discharged during 

 blossoming, after which the stamens generally fall off or wither away. 



238). But 



FIG. 235. Ptamcn of Tyrnla ; tho amhor oppiiins: by holes at the top. 



FIG. 230. Stamen of Barberry ; the anther opening by uplifted valves. 



FIG. 237. Stamen of Pentstemon piibescens ; anther-cells slightly confluent. 



FIG. 238. Stamen of Mallow ; tho two cells roiifluent into one, opening round the margin 



FIG. 2;}9. Anther of Globe Amaranth, of only one cell ; the other cell wanting. 



FIG. 240 Diagram of the lower part of an anther, cut across above, and the upper part of 

 a leaf, to show liow tho one answers to the other. 



