Page:Treatise on Cultivation of the Potato.djvu/48

 1. In immediate proximity.

4. Rich loam.

5. Ill ventilated.

6. No manure.

9. All affected more or less except about 5 per cent.

10. Not more than one per cent, by weight were affected.

13. This seems the only possible method of extinguishing the disease.

14. Most certainly not. The question is a national one.

I am sorry this gentleman forgot to give his address, his questions are so pertinent: as it is, in the hope of him seeing it, and of others appreciating it, I take the liberty of reprinting a Note on Mr. W. G. Smith's discovery of the Potato-Fungus, by W. Carruthers, F.R.S., Consulting Botanist to the Royal Agricultural Society of England:–

"Since the preceding Report was in print the hiatus in the life-history of the potato-fungus has been filled up by the discoveries of Mr. W. G. Smith, F.L.S., which has been communicated to the Scientific Committee of the Royal Horticultural Society, and for which their author has received that Society's gold medal. The structure and life of the Peronosopora Infestans, Mont., as found on the foliage, haulm, and tubers of infested potatoes, were previously well known and had been frequently described; but the conditions under which the life of the parasite is continued from the autumn to the following summer have been the subject of frequent, persevering, but hitherto unsuccessful research. At the instigation of the Royal Agricultural Society, Professor De Bary has renewed his investigations in this direction, and has arrived at important though yet unpublished results. So obscure has this part of the life of the fungus been, that some investigators have doubted whether the plant was a true Peronospora at all, and whether the desired information would not be discovered in some well known fungus parasitic on a different group of plants from the potato, and whose connection with the fungus of the potato disease had not been suspected.

The importance of Mr. Smith's discovery is all the greater that the subject was surrounded with so much obscurity.

It was in investigating the new aspect which the disease had assumed in some, especially in some American, varieties of potato