Proc. Roy. Socy. of Edin.] 
[Vol. XXY. 
Fig. 29. — Roots of Alnus glutinosa on the shore of Loch Ness that have been 
exposed by the action of the waves, and then continuously wounded by the 
stones of the beach being washed over them during floods. 
Fig. 30. — A transverse section of a wounded root of Alnus glutinosa, as shown in 
fig. 29, magnified three diameters. Nearly half of the root has been worn 
away ; the living portion below has again and again attempted to heal the 
wound by the formation of a callus, but the erosive action of the stones has 
frustrated this. The only living part of the root now is the light portion at 
the bottom of the picture. On the left an attempt is again being made to 
occlude the upper dead wood. 
Mr George West. 
[Plate 15 . — Referred to on page 995. 
