Communications. 283 



Any method of destroying the resting spores of these pests, or 

 of warding off or mitigating their attacks, obviously depends in 

 a great measure upon a full knowledge of their life history. That 

 life history I have endeavored to the best of my ability to watch 

 and de-cribe, and I am willing to let the ob-ervations stand on 

 their own merits. Sensibly conducted and extensive field ex- 

 periments might probably teach some valuable lessons, but it is 

 difficult, if not impossible, for any single individual, whether 

 farmer or botanist, to institute and carry out such experiments. 



Plate 5 represents the various stages of Peronospora infestans, 

 as described by Worthington G. Smith. 13 B B, cell tissue of a 

 potato leaf; A A, hairs of same; F and II, resting spores, con- 

 jugating; C, a conidial branch growing from the mycelium and 

 fruiting, showing its various stages up to perfect conidial (dust- 

 like) spores, G. 



FcsispoRiUM SoLANi AND ITS PvESTiNG Spores. — In reference 

 to this fungus, Mr. G. W. Smith sends us the following quotation 

 from an article which recently appeared in the "Gardener's Chron- 

 icle " from his pen : '' Fasisporium Solani is a fungus which very 

 commonly occurs on diseased potatoes in company with Peronospora 

 infestans. One is as destructive to the potato as the other, and 

 Mr, Berkele}'', writing of the former in 1857, described it as a 

 second enemy of the potato, equally destructive with the Per- 

 onospora, and, according as the two are separate or combined, dif- 

 ferent appearances arise. In some cas3s, continues Mr, Berkeley, 

 it produces an extreme degree of hardness, inducing a condition 

 like that of the mumified silkworms. Sometimes, on the con- 

 trary, it causes rapid and loathsome decay, especially when in 

 company with Peronospora, Like the latter, it suddenly appears 

 on the potato plant, carries on its work of destruction, and dis- 

 appears. Till now, I believe, the resting condition of Fusi- 

 sj)orium Solani has never been described. In my attempt to work 

 out the life history of Peronosponi injestans, the undoubted resting 

 spores of the Fusisporium came to light in the following manner : A 

 quantity of badly infected potato-leaves were selected and isolated 

 with the view of watching the Peronospora. As the presumed 



