120 THE STAMENS. 



diverge more or less widely from each other, and thus give the appearance of a one- 

 celled organ. In many plants the cells are either unequal, or one only is developed, as 

 in the Sage (Fig. 226 /), Canna, and the Arrowroot plant ; or after the commencement 

 of the process of development the two cells become confluent, and produce a single cell. 

 As each cell will have a separate line of dehiscence or fissure, a two-celled anther 

 will have two fissures, and a four-celled four fissures, and the latter is probably of 

 common occurrence. But besides the number of fissures, there are other points of dis- 

 agreement with the general law. Thus in a few instances the pollen is emitted not by 

 a fissure, but by small holes, or perforations ; or the fissure does not occupy the whole 

 length of the cell ; or the cells burst first into each other, and then have a common dehi- 

 scence ; or a large portion of the whole face of the anther comes away in a piece (Fig. 

 228 /;). But however much so minute a matter may vary, it is of importance to bear in 

 mind that it proceeds on a fixed plan, and that its whole organization has a known 

 correspondence with it. 



"When the line of dehiscence is towards the petals, the anther is said to be extrorsa, 

 and when inwards towards the pistil, it is called introrsce. The lining membrane of the 

 cells is called Endothecium, and usually consists of fibro-cellular tissue, whilst the pollen 

 occupies the position of the normal parenchyma. 



The Pollen. The parts of the stamen already described seem to include in their 

 analogies the whole leaf; for the filament represented the petiole, and the anther the 

 lamina, with the parenchym in which the pollen is deposited. But yet there is another 

 and the most essential part of the stamen as yet undescribed, and one which has also 

 its analogies in the leaf itself. This substance is known as the pollen, and is the imme- 

 diate source of fructification. It is a powdery substance of various colours, but more 

 commonly colourless, as may be noticed upon any fully-developed flower. It is 

 that material which is shaken like dust from the flower, and which is not un- 

 frequently adherent to the nose when that organ is searching out the sweet odours of 

 flowers. 



Its normal position is the anther case, where it remains until it has arrived at a 

 stage of maturity fitted for the performance of its functions, 

 when it is emitted by the dehiscence or sudden rupture of the 

 anther, or pollen case, and is ultimately deposited upon the free 

 end of the pistil. The quantity of small grains of pollen upon 

 a single stamen is immense infinitely greater than is needful for 

 the fertilization of the pistil ; but that is a wise arrangement to 

 insure fructification, despite the influence of winds, the sterility 

 of some of the stamens, and the irregularly-placed pistil. If our 

 readers will examine any half-dozen plants, which may be near 

 to them, in full bloom, and notice the relative height of the 

 pistils and stamens, they will wonder not why so great a waste 

 of pollen has been provided by nature, but that the fertilization 

 exhibiting pollen should be effected with so much certainty. The improbability of 

 this occurrence is of course greater where the male and female 

 parts do not exist in the same flower ; yet not only does it pro- 

 ceed regularly where there are separate flowers for nvdes and others for females, but 

 in our large forest trees, in which one tree has male flowers only, and another 

 only female flowers. In such cases the pollen is carried by the wind that very \ 

 influence which at first sight seemed more likely to cause an entire waste of the I 

 _ J 



