2 14 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



The questions submitted to observers were as follows : — 



A. — Common Larch [Lan'x evropced). 



General. 



1. Is the disease known as "Canker" or "Blister" common in 



your crops ? 



2. On what geological formation or formations do the crops 



grow ? 



3. On what kinds of soil do they grow ? 



4. On what aspects do they grow ? 



5. Is the natural drainage of the soil good? 



6. Have you found the disease to be more prevalent on trees 



growing on low-lying ground or in hollows than on those 

 growing on high exposed ground ? 



7. Do you consider that the wetness or dryness of the soil in 



which the plants grow has any effect on the disease? 



8. Is there any particular age at which the tree seems most 



liable to attack ? 



9. What is the earliest age at which you have observed plants 



to be attacked ? 



10. Have you ever observed diseased trees to recover? 



11. Do you know of any crop which is quite free from disease^? 



12. Do you consider that the disease is increasing or 



diminishing ? 



Climatic and other Physical Agencies. 



13. Have you ever observed disease to follow — {a) A severe late 



spring, summer, or early autumn frost? {b) A violent 

 hailstorm ? {c) A heavy fall of snow causing bending of 

 the branches? (d) Any other climatic agency? (<?) Any 

 physical agency other than climatic ? 



Insects and Other Animals. 



14. Have you ever observed disease to follow attack by Aphis, 



the caterpillar of the larch-mining moth, or other insect? 



15. Have you ever observed disease to follow injury from 



animals other than insects ? 



