120 MISS 8. LONGMAN ON THE DRY-ROT OF POTATOES. 
The Dry-Rot of Potatoes. By Sigyz Loneman, Research Student in Botany, 
University College, Reading. (Communicated by Prof. Е. KEEBLE, 
D.Se., F.L.S.) 
(PLATE 10.) 
` Read 18th March, 1909.7 
I. INTRODUCTION. 
THE objects with which this research was undertaken were :— 
(1) To determine whether the fungus cf dry-rot of potatoes (Fusarium 
Solani) is capable of. inducing disease in the growing potato plant, 
as well as of setting up the well-known pathologieal condition in 
the stored tuber. 
(2) To ascertain whether dry-rot can be induced in potato-tubers 
directly by inoculation with spores of Fusarium Solant, or whether, 
as is commonly supposed, dry-rot only follows upon wet-rot. 
(3) To determine experimentally whether tubers infected by F. Solan: 
an be sterilized by heat, i. e. whether the death-temperature of the 
fungus is higher or lower than that of the tuber. 
With respect to (1) the conclusion is reached that К. Solani is a true 
parasite not only of the resting tuber but also of the growing potato-plant. 
With respeet to (2) it is shown that there is no necessary time-relation 
between an outbreak of dry-rot and one of wet-rot. Dry-rot may be induced 
by inoculating healthy potato-tubers with pure cultures of F. Solan spores. 
These conclusions, arrived at independently, confirm those reached at an 
earlier date by Smith and Swingle and published in their memoir on the Dry- 
Rot of Potatoes (704). 
Among the other conclusions reached in this paper may be mentioned those 
relating to the systematic position of the fungus. Whilst reasons are given 
(р. 123) for assigning Fusarium Solani io а place among the Ascomycetous 
fungi, no support is offered to the claims of Massee (704) that F. Solan 
possesses a definite ascus-stage. 
П. Тнк SYMPTOMS or THE DISEASE, AND THE LIFE-HISTORY OF 
Fusartum SOLANI. 
Fusarium Solani causes the potato disease known as ** dry-rot." In autumn, 
when potatoes are being harvested, a few may be seen already showing 
symptoms of dry-rot, but the disease is far more wide spread amongst stored 
