PKATK \I,I\' 



•'e * 





Fig. 1.— Rock Colonisation : A Bare Slab of Kock in a Fort-st showing ,i 

 Primitive Soil composed of Finc-necdles. 



Fk;. J. The Lielun {I'.'nini) urowiiig on the linmclies of a Coniferous Tree. 



[Tojacf ;>. 23S. 



