94 Forestry Quarterly. 



It has been noticed in forests (especially beech) that wherever 

 this reflected light gets a chance to operate on the forest floor, 

 the ground flora is more scanty. 



The greater the heat and intensity of the light and the less the 

 rainfall, i. e. the supply of ground water available, the greater 

 the injury done by this reflected light, especially from broad- 

 leaved, thick- foliaged trees with shiny leaves. The damage is 

 also influenced by the susceptibility of the affected plants to this 

 reflected light. G. E. B. 



Das "Brennen" der Waldb'dume. AUgemeine Forst- und Jagd Zeitung. 

 October, 1912. Pp. 336-342. 



A disease of young elms was first observed 



Blm in a nursery at Stockholm in 1905. A later 



Twig study showed it to be due to an undescribed 



Disease. species of E.vosporium which killed the 



twigs at the tips of the plant, or over the 

 entire crown, often causing the death of the smaller stock. The 

 disease was confined to Uimus montana, U. montana oxoniensis. 

 U. campestris and U. effusa. While most serious on young nur- 

 sery plants it also occurs on various-sized trees under natural 

 conditions. In one locality it is said to have been destructive 

 long before 1888, but most of the outbreaks in different parts of 

 Sweden have been noted during the past five years. 



The black fruiting-pustules are grouped on the dead areas, 

 particularly in the axils of the small limbs, causing an irregular 

 rupture of the epidermis. Infection experiments with young 

 elms in the greenhouses, by applying conidia to the internodes of 

 the delicate green shoots of the year, prove that the fungus is 

 pathogenic and requires an incubation period of about ten 

 months. The development of the disease was studied on trees 

 of different age in the experimental garden. This study led to 

 the conclusion that infection takes place through the young 

 shoots of the season, these being wholly or partially killed by 

 the following May or June, but remaining at least another year 

 on the tree and bearing black pustules far into the summer. 

 The second spring, almost without exception, a red Nectria ap- 

 pears; however, the authors have not yet shown this to be the 

 perfect stage of the Exosporium. There seems to be a second 

 method of infection on 2-4 year old branches by the mycelium 



