The Potato Fungus. By Worthington G. Smith. 121 
whicli the resting spores were present in sealed bottles, each bottle 
containing 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. In former 
numbers of the ' Gardeners' Chronicle ' I have described how these 
resting spores at first floated on the surface 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 my spores retained their vitality. 
Mr. Broome, being equally uncertain with myself, trusted to chance, 
and chance so far favoured him that all his resting spores in the 
slanting saucer of water well retained their life. It might have 
been (and even 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 in 
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 difficulty 
almost amounts to an impossibility. The fungi under study 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 that is desired to be preserved. 
Now one of the most extraordinary facts about the recent 
Potato investigations in this country is this. These other fungi 
and infusoria have not to any damaging extent appeared. Since 
I opened my sealed bottles last April I have kept the material 
under a bell-glass, and there has been no offensive odour, and to 
no appreciable extent have there been any moulds, infusoria, or 
parasites, except Peronospora infestans itself, and the other 
fungus which is equally destructive to potatoes, known under 
Fusisporium Solani. In investigating the Potato disease it was 
almost as important to discover the entire life history of the 
Fusisporium as the Peronospora, and fortunately the materials 
preserved gave a perfect clue to the entire life history of both. 
Mr. Broome's material has in the same manner been free from an 
excessive number of other fungi and infusoria. 
The germination of the resting spores was awaited with the 
greatest anxiety ; and as I never knew from one day to another 
whether or not these bodies might all collapse and perish, I was 
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