54 



THE GARDENER'S MONTHLY 



[February, 



up the Clyde to Glasgow, and found that where 

 the fog, in place of floating, covei'ed its banks 

 like a blanket, and where there was no frost, of 

 course, that not a potato was injured. 27th of 

 August I strolled up past old Bothwell Castle to 

 near to Corrie Lynn and still no potato blight. 



It is certainly true that put diseased potatoes in 

 a cellar they will rot, but that has nothing to do 

 with what made them diseased. I once dumped 

 into a covered cave 800 bushels of sound potatoes. 

 The weather was wet, and a good deal of clay 

 stuck to them. About mid-winter I found them 

 heated and half rotten, which I certainly never 

 would have thought of charging to fungus. The 

 same with 200 or 300 bushels of sound turnips that 

 after being carefully topped were piled away in 

 a corner of the cellar that soon began to grow 

 and then to heat, and which, if they had not 

 been immediately scattered, would all have been 

 lost. I was lazy, Mr. Meehan, about sending you 

 my last communication, and as much so this 

 time, but having written, and my conclusions 

 about potato rot thought to l)e wrong, I want you 

 and j'our correspondents to pitch into me. as it is 

 only/ods that I am after. 



[Can our correspondent explain why no " frosts," 

 "heats," "damps," or "fogs," had these destruc- 

 tive eff"ects previous to 1846?— Ed. G. M.| 



TOBACCO AS MANURE. 



BY W. H. JJ1..VXCIIARI), WOKClXrKR, VKRT. 



II. L. can best see the value of Tobacco waste 

 by comparing its nitrogen and ash constituents 

 with other plants, as meadow-hay, and wheat- 

 straw and grain, as given by Prof. Wolfi; of IIo- 

 henheim : 



Water. Ash. Nitrogen. Potash. Phos. 



acid. 



Tobacco, 180 197.5 4G 54 7 



Meadow-hay, 144 GG.6 13 17 4 

 Wheat-straw, 141 42 3.2 5 2.3 



Wheat-grain, 143 17 20.8 5.5 8 



The table shows the innnber of pounds of 

 water, nitrogen, total ash, potash, and phosphoric 

 acid in 1000 lt>s., air dry. 



It will be seen that tobacco is the most valu- 

 able plant we raise for manure, being worth three 

 times as much as meadow-hay. In practice, farm- 

 ers consider tobacco-stalks and waste of great 

 value, and apply it to the land, some directly by 

 plowing in, and others by composting it with 

 stable manure and allowing it to decompose; 

 which latter is the better wav. 



RESTING SPORES OF THE POTATO FUNGUS. 



BY J. G. HUNT, M. D., PHILADELPHIA. 



In accordance with your request, I send you 

 the following : 



There are three diseases, apparently, afflicting 

 the potato. First, the jiotatoes may be gathered 

 apparently sound, but after being housed a short 

 time, many of them and often the entire crop, 

 are found soft and in a condition of decay. 



Secondly, many tubers are nearly or entirely 

 filled with hard concretions, while only a small 

 I)art is seemingly healthy, but the entire potato 

 remains dry. 



The third diseased state — if it be really distinct 

 from the other conditions — I have more carefully 

 examined. The potato presents many irregular 

 excavations on the surface, extending often 

 deeply into it. These excavations on carefulest 

 examinations present no trace of igsect ravages. 

 The sides and entire circumference of each pit 

 are bounded by shrunken, irregular cells desti- 

 tute of starch granules. On making very thin 

 sections entirely across these excavations and 

 l^roperly treating the sections, a careful micro- 

 scopical examination reveals the following facts: 



In many of the empty cells next the boundary 

 of the excavation are beaded filaments of a fun- 

 gus, two or more round cells, with the terminal 

 one often presenting a point. Mycelial filaments 

 obscurely septate ireep all among these cells, 

 and extend, back into and among the more nor- 

 mal cells, in which the starch is still in a natural 

 state. On many of these mycelial threads in the 

 still full cells are oval or round bodies, about the 

 one eight himdredth of an inch in diameter, 

 each containing one or more distinct nuclei. 

 The cells containing these bodies — which, prob- 

 ably are resting spores or oogonia — are generally 

 de.'^titute of starch, though a few grains often re- 

 main, but are altered in structure, being rough 

 and broken into fragments. It is apparent, that 

 no insect could produce ravages similar to these, 

 I am, therefore, convinced that a fungus is the 

 cause of this form of disease, and that the plant 

 is Peronospora, and that the resting spores are 

 placed where they are in order to get nutrition 

 through their resting stage in order to perpetuate 

 the fungus in the coming season when the new 

 croj^ shall be planted in the spring. 



[At a recent meeting of the Academy of Natu- 

 ral Sciences, Philadelphia, Dr. J. Gibbons Hunt 

 announced the discovery of what he believed to 

 be the resting spores of the potato fungus in 



