THE POTATO FUNGUS. 
19 
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 foi'mer 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 spoi es 
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 tbe 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 potatos, and known under 
Fusisporium Solani. Mr. Broome’s material has in the same 
manner been free from an excessive number of other fungi and 
infusoria. 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. 
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 
under the necessity of dividing the material, and keeping a constant 
look-out lor results under different conditions. With this object 
ill view, therefore, I kept some of the bodies moist in pure water, 
