DAMAGE CAUSED BY PLANTS. 73 



unknown, and treated with contempt, whilst in the case of others, 

 cause and effect were confused, the appearance of many fungi, 

 (e.g., species of Polyporus), being regarded as the consequence of 

 rot instead of its cause. Not a few of these phenomena still 

 remain unsolved riddles to the Sylviculturist. 



Among many other scientists and observers, Professor Eobert 

 Hartig of Munich has been foremost in studying this branch, in 

 clearing up many of its mysteries, and in giving practical hints 

 as to how the results of his investigations can be of practical use 

 in forestry. For the scope of this little work, confined to the 

 Protection of Woodlands, the latter alone are strictly of interest. 

 We may perhaps, however, be allowed to remark that it is expected 

 of the well-informed forester that he should know the reason of 

 the sickening and dying off of the trees and plants under his 

 charge, even although in many cases preventive and remedial 

 measures against the causes have not yet been discovered. 



For a closer study of the diseases of plants generally, and 

 of those occasioned by fungi in particular, E. Hartig's Lehrbuch 

 der Baumkrankheiten, 2nd Edition, 1889, is to be recommended. 

 In accordance with the consistent aim of this little work, only the 

 more important, and more frequently occurring, fungal diseases, 

 capable of being obviated by practical measures, are referred to in a 

 short sketchy manner, the data being drawn from the above work. 



(1) Fungi on Leaves and Needles. 



The Beech-seedling fungus (Phytophthora omnivora P.fagi), prin- 

 cipally occurring on the cotyledons of Beech-seedlings, but also on 

 those of the Maple and Sycamore, the Spruce, Silver Fir, and 

 Larch, makes itself apparent by the blackening of the shoots, 

 cotyledons, and primordial leaves, or by the breaking out of black 

 I spots on these, which is soon followed by the death of the seed- 

 lings. In consequence of this fungus, whole seed-beds, covered 

 with rills of coniferous sowings, may be killed off even before the 

 germinating seedlings have made their appearance above the soil. 

 This disease occurs extensively in seed-beds, and especially in 

 seed-fellings during the natural reproduction of the Beech, par- 

 ticularly when the spring weather is damp and warm. As the 

 spores are easily carried along by men and animals, the dying off of 

 the young seedlings is usually very apparent along paths and road- 

 ways leading through Beech-woods undergoing natural regeneration. 



