312 PLANT LIFE. 



Sphaeriaceae and of these Heterosphaeria patella seems 

 the commonest in Scotland. 



Most of these complicated processes are carried on 

 out of sight, and it is only by carefully examining dead 

 logs and old stumps, that the evidences of these activities 

 can be observed. The number of Agarici seen in 

 Autumn, gives some idea of the importance of these 

 Fungi. The production of a single Agaricus involves a 

 very extensive system of branching, mycelial threads 

 within the soil, and their abundance shows that the 

 humus and decaying matter must be woven together, 

 and pierced in every direction by mycelia. Thus the 

 absorption system of the wood is a very complex one, 

 in which Fungi, Bacteria, and insects of many kinds, as 

 well as worms and other animals, are the most important 

 factors. 



If the trees are blown down by a storm, or if the wood 

 is cut down, the process of regeneration takes many 

 years, and is generally marked by a series, or succession, 

 of intermediate plants. This series is roughly speaking 

 as follows: (i) Herbaceous plants; (2) Bramble or 

 Raspberry Brakes ; (3) Hawthorn, Rowan, and Birch ; 

 (4) Forest trees. After the trees have fallen, the 

 numerous seedlings of woodland flowers find the 

 conditions extraordinarily favourable to themselves. 

 Campions, Bluebells, Woodruff, Stachys, and others spring 

 up by hundreds and thousands, and produce a brilliancy 

 of colour exceedingly unusual in a sombre country like 

 Great Britain. These herbaceous forms may flourish 

 for two or three seasons ; and, if they do so, taller forms 

 such as Foxglove, Angelica, and others appear in pro- 

 fusion. Besides these specially woodland plants. Thistles 

 and Nettles will grow in abundance, if there is a large 

 supply of their seeds available. After this herbaceous 



