LARCH DISEASE. 45 



9. Is the disease hereditary ? that is to say, is it trarismitted 

 through seed ? The disease itself is not directly transmissible 

 through seed. But an inherent tendency to the contraction of 

 the disease, or to immunity therefrom, is transmissible ; and for 

 this reason it is |ti-udent to avoid collecting seed from trees whif^h 

 have actually contracted disease. 



10. Is it likely that the disease originates in nurseries, and is 

 conveyed along loith the plants to youny jdantations ? If a pre- 

 disposition to disease is inherent in certain trees, and if this 

 predisposition is transmitted through their seed to their progeny, 

 it follows that when these latter are planted out they have this 

 tendency inherent in them. It was asserted that actual disease 

 occurs in nurseries. In such a case, even though plants that are 

 visibly affected may be destroyed, it is evident that others, in an 

 earlier stage of the disease, when its detection by superficial 

 examination is impossible, must escape observation, and be planted 

 out when in a diseased condition. 



11. Relative resistance to disease of larches raised from home and 

 foreign seed. Very little evidence, drawn from practical experi- 

 ence, was adduced ; but the great majority of British planters 

 would prefer plants raised from home-grown seed. 



12. Are self-sown larches s-pecially resistant to attack? There 

 was a preponderance of evidence in favour of self-sown larches 

 enjoying comparative immunity from attack, such immunioy 

 being probably due to the fact that when plants are left to grow 

 into trees on the spot where the seed was sown, they are not 

 subjected to risks of injury during lifting, transport, and planting. 



13. Do diseased ^:»^an<s ever completely recover? When once 

 the disease has obtained a footing on a tree, a return to a healthy 

 condition cannot be looked for. Death, as a consequence of the 

 disease, may, however, be delayed for a long time, and much 

 good, useful timber is often formed after trees have contracted 

 the disease. 



14. Cure or mitigation of the disease. If the blister spot be 

 carefully dug out with a knife or chisel, and the wound be after- 

 wards dressed with grafting-wax or coal-tar, recovery at the spot 

 so treated may be expected, but such treatment could hardly be 

 applied otherwise than to a specimen tree which it might be desired 

 to retain at any cost. As regards mitigation, in the majority of 

 cases the most important measures would appear to be these, 

 viz. : — Cultivate the larch in mixed woods ; avoid planting in 



