ioo ABOUT A FERN. [CHAP. 



a pale brown colour, composed of cells, one row of 

 which has thicker walls than the rest, and thus forms 

 a band round the edge of the case. This case is 

 botanically termed a sporange (fig. 95, b\ and the clus- 

 ters of them are spoken of as sort. They contain the 

 exceedingly minute spores, which are visible to the 

 naked eye merely as a fine dust. When these spores 

 are ripe their increased size exerts such pressure 

 upon the sporange that the elastic ring of cells is 

 ruptured and extended out straight ; a transverse 

 split occurs in the sporange, and the spores are scat- 

 tered by the violence of the rupture (c). We shall in 

 all probability observe this taking place among those 

 under our microscope. Suppose that these spores are 

 scattered in their natural habitat, say upon some damp 

 mossy stone, or hedge-bank; in a sheltered spot, where 

 there is thorough moisture. They germinate. First 

 a little tubular process shoots out from the spore (fig. 

 96, b) t and from the under side of that another similar 

 process is developed and becomes the first rootlet. The 

 tubular process from which it was developed divides 

 into cells, which again divide and subdivide, until they 

 form a tiny kidney-shaped green disc which gives off 

 from its under surface very minute fibres which attach 

 it to the soil. This little flat green expansion is known 

 as & prothalhis (d). On its under surface it gives rise 

 to the reproductive organs, which are known only by 

 theirscientific names. They are of two kinds, and ana- 

 logous to the stamens and pistil of flowering plants. 

 The first of these is called the antheridia (d, 2), and 

 are found among the rootlets; the second is known as 

 the arckegonia(d,^), and are produced on a thickened 



