202 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



available on this point, but it is proposed to carry out infection 

 experiments to throw light on this and other questions in con- 

 nection with the life history of the fungus. 



Description of Plate II. 



Fig. I. — Photograph of twig of Larix airopcra with diseased leaves: (a) 

 pseudoperidium with lacerate margin ; {b) unopened pseudoperidium ( X4). 



Fig. 2. — Photograph of twig of ditto, with fused pseudoperidia (X4). 



Fig. 3. — Photograph of twigs of ditto (about natural size). 



Fig. 4. — A pseudoperidium showing lacerate margin ( x about 50). 



Fig. 5. — Spore in surface view ( x 1000). 



Fig. 6. — Spore in optical median section ( x 1000). 



Fig. 7. — Part of pseudoperidium ; the lower cells show the verrucose marking 

 on the walls ( x 220). 



24. Recent Publications on Swiss Forests. 



By W. S. Smith, Ph.D. 



The problem of afforestation requires, as most will admit, 

 careful consideration of all conditions of the area, and it is well 

 to regard what is being done in other countries. The members 

 of the Society are to have this year the opportunity of seeing 

 Swiss forestry, and several recent Swiss papers deal with forests. 

 Two of the authors referred to below spent several weeks in 

 Britain in 191 1 and visited woodlands in all parts, so that they 

 are in a position to make valuable comparisons. 



Professor C. Schroeter of Zurich, ^ in comparing the vegetation 

 of Britain and Switzerland, points out that in both countries man 

 has had a great influence on the present condition of the woods. 

 Both countries have below the tree limit a typical forest climate, 

 so that the natural vegetation of the land, if left to itself to grow 

 without restriction, would become forest and remain in this state 

 with forest as a " climax plant formation." Exceptions to this 

 rule occur on the salt marshes, shingle beaches, and moving 

 sand dunes on our coasts, on certain shallow calcareous soils 

 like the Chalk Downs, on many poor sandy soils, in wet marshes 

 and peat bogs, and on the slipping banks along streams or 

 below crags. Man has made extensive inroads on what were 

 formerly great areas of forest. In Switzerland, out of every 



^ C. Schroeter in New Phytologist, xl., pp. 277-289, 1912. 



