120 PRESIDENT S A^DDEESS. 



of an antlier is one or more lobes, but usually there is also a 

 stalk or tilament. Anthers may be truthfully called staminal 

 leaves, the lobes or pollen sacs being formed by foldings of the 

 halves of the leaf-blade ; the filament and connective being the 

 midrif. The filament may be wanting, when the lobes become 

 sessile ; or prolonged beyond the lobes, as in Herb Paris ; but it 

 usually ends at the lobes in the connective. Occasionally the 

 lobes are apart, on equal branches as iu Hornbeam, or unequal 

 as in Salvia. Most anthers have two lobes, and each lobe one 

 or two sacs or loculi, so that most anthers are either quadri- 

 locular or bilocular. Very rarely four sacs are found in one lobe. 

 Many anthers in an early stage of development are quadrilocular, 

 but when mature become by absorption bilocular. The flower- 

 ing rush is quadrilocular throughout. Others are bilocular in 

 an early stage, and later become unilocular as the Milkworts. 

 In ordinary Angiosperms when the anther is mature the pollen 

 lies in separate grains in the four loculi, and falls out when the 

 anther opens, as it does in various fashions. 



When the anther is mature and the pollen falls out, it reaches 

 in various ways the female organ and produces therein fertiliza- 

 tion. The act of conveying pollen to the Angiosperm stigma 

 or Gymnosperm naked ovule is called Pollination. It may be 

 secured by wind as with the Coniferce, many forest trees, and 

 cereals generally ; or by insects or birds as with Orchids, Vanilla, 

 etc. ; or by mechanical means or movements on the part of the 

 flower itself, as in Berberis by irritability of stamens ; in Grass 

 of Parnassus, by successive elongations of stamens ; in Urticaceee, 

 by a sudden bursting of the anther; in Epijjactis, Oncidium, 

 and other orchids, by a bending forward of their pollinia, so that 

 they stick by their rostellse to the heads of bees and other 

 insects ; by trapping within the flower an insect, as in Aristo- 

 lochia Clematitis ; by floating of the male flower, as in some 

 aquatic plants and by various other ways. Often the act of 

 opening the flower lips to enter for honey leads to a sudden 

 discharge of pollen. Thus Melamjujrum sylvaticum, Lamium 

 purpureilm, and the Greenhouse Genista exhibit this amusing 

 phenomenon, that when the base of the flower is lightly pinched 



