27-8 "Wisconsin State Horticultural Society. 



Montagae's Artotrogus and the bodies discovered by me, are tbe 

 same. That both belong to Peronospora the sequel will prove. 



It was of the highest importance that these resting spores should 

 be preserved alive until the time arrived for their renewed activity, 

 and with this purpose in view I preserved the material in which 

 the resting spores were present in sealed bottles, each bottle con- 

 taining more or less pure water or expressed juice of horse-dung 

 diluted with water. As I was quite in the dark as to the habits 

 of these resting spores, of course I did not know what to do for 

 the best, or what the result of my experiments would be. I have 

 described before how these resting spores at first float on the sur- 

 face of the water, how they at length deposited themselves in the 

 sediment at the bottom, and how, on opening one of the bottles 

 at the last meeting of botanists at Hereford, the resting spores 

 were found still intact and apparently alive. Happily, nearly all 

 the spores retained their vitality. Mr. Broome, being equally un- 

 certain with myself, trusted to chance, and chance so far favored 

 him that all his resting spores in the slanting saucer of water re- 

 tained life. It might have been (and ever was) said that possibly 

 some fungus foreign to the potato-fungus had got into my material, 

 but if so, it must be regarded as a coincidence in the highest 

 degree extraordinary that Mr. Broome should also get the same 

 new and foreign fungus ia his Peronospora material — a body so 

 puzzling in its nature as to be referred to no less than eight 

 different species of fungi. 



All who have studied the habits of the lower fungi know the 

 extreme difficulty of preserving the specimens alive. This diffi- 

 culty almost ^mounts to an impossibility. The fungi understudy 

 may be present one day and all gone the next ; a few drops of 

 extra moisture or a slight current of dry air is sufficient to destroy 

 or collapse the whole lot. Besides this, myriads of other parasitic 

 fungi and whole tribes of infusoria commonly make their appear- 

 ance and prey upon the material it is desired to preserve. 



Now one of the most extraordinary facts about the recent 

 potato investigations in this country is this : These other fungi 

 and infusoria have not appeared to any damaging extent. Since 

 I opened my sealed bottles last April, I have kept the material 



