374 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



portions of the bulb that have been more or less weakened by other 

 agents ; there is undoubted evidence to show that the mite will pass on 

 from diseased to sound portions of a bulb, but, so far as I can ascertain, 

 there is no reason for believing that the mite attacks sound bulbs, thus 

 originating a disease. 



Owing to the size of the conidia and other differences, Professor 

 Marshall Ward could not reconcile the Botrytis causing the Lily disease 

 with that of any species described in books, and consequently did not 

 assign to it a specific name. I have had the species under observation 

 for the past ten years, and, from artificial cultures carried on under very 

 varied conditions, have come to the conclusion that we are dealing with a 

 highly specialised form of Botrytis cinerea Pers., which, as I have shown 

 elsewhere in this Journal (5), is a very variable species, and capable of 

 undergoing material modification in matters of detail in its various 

 specialised forms. No ascigerous condition has been observed as forming 

 part of the life-cycle of the Lily Botrytis. 



Preventive Measures. — Most unfortunately, notwithstanding the 

 appearance of innumerable articles couched respectively in persuasive and 

 sarcastic terms, commenting on the tardiness of plant cultivators in adopt- 

 ing preventive measures against plant diseases caused by fungi, the 

 almost total absence of the exercise of such measures would suggest that 

 the practical man had no confidence in the advice given by the mycologist. 

 The saving clause against this opinion is the fact that mycologists and 

 editors are flooded with diseased plants when a given epidemic has reached 

 such a stage that the only possible reply is — Too late. 



Taking our preventive measures piecemeal : — Assuming we have a 

 bulb free from Botrytis, it is only fair to suppose that the mycelium of 

 the fungus is present in the soil. To guard against infection, make a hole 

 in the soil three or four times the size of the bulb, fill it with quartz sand 

 in which a dessert spoonful of sulphur has been mixed, and plant the 

 bulb in the middle of the sand. By adopting this method we practically 

 prevent the formation of sclerotia on the bulb, as mycelium cannot pass 

 through sand owing to lack of food. 



A gardener whose land was evidently infested with Botrytis mycelium, 

 and whose Lily bulbs were in consequence destroyed annually, undertook, 

 amongst other preventive measures, to plant his bulbs in sand. He after- 

 wards informed me, according to agreement, of the result, and apparently 

 quietly enjoyed stating that the experiment was a failure : " the Lilies kept 

 clean and did well for three years, and the fourth year the disease showed 

 again." I then suggested replanting bulbs in sand every fourth year, 

 and the reply was "that would be a good plan." This particular 

 gardener was an admitted expert, and within his own cii^le of light could 

 be relied upon ; but, unfortunately, preventive measures against disease 

 were a subject outside his circle, and consequently considered as of very 

 minor importance. 



Returning to preventive measures : — The surface soil covering bulbs 

 should be removed every autumn, and replaced by soil mixed with kainit, 

 which destroys fungus mycelium. For the same reason, manure used 

 for mulching should be mixed with kainit, which practically sterilises it, 

 and at the same time is in itself a good fertiliser. 



