PLANTING OF QUICKER GROWING CONIFERS. 145 



of the initial planting of much greater quantities of young plants 

 to the acre. In any case, it seems clear that what may be 

 reasonably close for ordinary conifers is unreasonably, and even 

 disastrously, close for the quicker growing kinds. 



P.S. — It may be convenient to append the table of plants 

 required per acre (square planting). 



3 feet apart 4840. 6£ feet apart 1031. 



7 „ 889. 

 7i ». 774- 



8 ,, 680. 

 H „ 603. 



9 .. 537- 



17. A New Disease of the Douglas Fir in Scotland. 



( With Plates.) 



By Malcolm Wilson, D.Sc. (Lond.), F.R.S.E., F.L.S., Lecturer 

 in Mycology in the University of Edinburgh. 



More than ten years ago my attention was directed by 

 Dr A. W. Borthwick to specimens of the Douglas fir in which 

 the leading shoot had been killed for a distance of 6-12 inches 

 behind the apex. The trees were from 6-10 years old, and he 

 suggested that the damage was not due, as was generally 

 supposed, to frost. A few years later other similar specimens 

 were received, and in these the fructifications of a species of 

 Phoma were present on the dead shoots. Observations were 

 then interrupted by the war, but during the last eighteen months 

 numerous specimens have been obtained, many of them through 

 the headquarters of the Forestry Commission in Scotland, and 

 examination has shown that the disease is undoubtedly caused 

 by a species of Phomopsis, a sub-genus of the large genus Phoma. 



Specimens of the Douglas fir attacked by the disease have 

 been received from several localities in Perthshire, from near 

 Forres, and from Argyllshire, Dumfries and Inverness, and it 

 may be concluded that the disease is widely spread in Scotland. 

 The disease has been observed in trees up to about 10 years 

 old, both in nursery stock and in plantations. 



Two types of attack may be distinguished. In the first, the 

 leading shoot (or occasionally a side shoot) is killed back for 

 a variable distance, usually about 9 inches (Photos 1 and 2, 



