80 ANTHER. POLLEN. 



1st. Upon the internal parietes qftJie tube of the 

 J corolla, when it is monopetalous, as in the lilac. 

 Fig. 107 represents the flower of a primrose opened, 

 showing the pistil (a) and the stamens (&) attached 

 to the corolla (c). 



2d. Upon the ovary, which takes place when the 

 Fig. 107. corolla is epipeHalous, as in umbelliferous plants. 

 3d. Beneath the ovary, which happens when 

 the corolla is hypope'talous, as in the poppy, the cruci'fera, the 

 vine (fig. 115), &c. 



4th. Upon live calyx, which always occurs when the calyx 

 bears the petals, as in the rose (fig. 82). 



46. The corolla always has the same position as the stamens ; 

 in all monopetalous corollas, the stamens are attached to the 

 corolla, and in all polype'talous flowers the stamens are not 

 attached to the corolla. 



47. Anther. The anther is the most essential part of the 

 stamen, and occupies its summit (fig. 103, c); its colour is almost 

 always yellow, and it may be compared to the limb of a very 

 small leaf, that has become thickened, narrow, and folded upon 

 itself. In its interior the pollen is formed,- and it ordinarily con- 

 sists of two small membranous sacks, named cells or lodges, 

 which are joined together back to back, or by a portion of the 

 superior extremity of the filament, called the connective. Some- 

 times there is but one of these cells, which seems to be owing 

 to the abortion of one of these pouches, or to the bifurcation 

 of the filament; and at other times there are four. There 

 are some also that are divided internally by partitions. The 

 form and mode of insertion of the anthers vary ; sometimes 

 these organs are elongated, at other times rounded, cordiform, 

 &c. Sometimes they adhere to the filament for a great part of 

 their length ; at other times they are attached by one of their 

 extremities only, and at other times again, they are fixed at their 

 middle upon the very extremity of the filament. 



48. Pollen. The pollen is a yellow dust that is enclosed in 

 the cells of the anther, which by falling upon the pistil causes the 

 development of germs and the formation of seeds. It is composed 

 of extremely small grains, the surface of which is sometimes 

 smooth, sometimes covered by asperities, and their interior is 

 filled with extremely fine dust. The envelope of these grains of 

 pollen is composed of two membranes, and when they come to be 



46. Where are the stamens attached in monopetalous flowers ? Where 

 are they attached in polypetalous flowers ? 



47. Describe the anther. What is meant by the connective ? Is the 

 form of all anthers the same ? Are their attachments alike in all flowers ? 



48. What is pollen ? Where is it formed ? What is the use of it ? 



