THE VASCULAR CRYPTOGAMS 



are colourless and destitute of leaves ; they grow straight 

 down to the soil and resemble roots, but have no root- 

 caps. On coming into contact with the ground they 

 branch, giving rise to subterranean rootlets, which have 

 root-caps as usual. 



If the plant which we examine is fruiting, we shall 

 find that some of the branches, 

 instead of creeping along near 

 the ground, grow straight 

 upwards ; it is these vertical 

 branches which form the 

 terminal spikes or cones. 

 The cones bear the repro- 

 ductive organs ; they differ 

 from the vegetative branches 

 in the fact that all their leaves 

 are of the same size (see Figs. 

 1 and 3). 



Other species of Selaginella 

 differ very widely from that 

 just described. 



Some are minute creeping 

 plants of almost microscopic 



dimensions, with unbranchecl FlG - s.Selaginclla helvetica, 



. showing procumbent stem 



Stems (& Simplex) ; Others have and two fertile spikes, r, 



climbing stems, which ascend rhizophore ; y, /P ^- 



Slightly magnified. (After 

 tall trees, and may attain a Dodel-Port.) 



length of 6 feet (S. exaltata) ; 



while in others again the stem is stiff and erect, rising 



vertically to a height of three feet from the ground (S. 



grandis). 



A still more important variation is in the arrangement 

 of the leaves. The majority of species agree with S. 



r 



