I. AGRICULTURE AND RURAL ECONOMY. 407 



disease and the best methods of its prevention. Ninety-four 

 essays were sent in for competition, none of which, however, 

 was considered as satisfying the conditions. Among the 

 principal causes adduced by a large majority of the writers 

 as bringing about the disease were : First, the degeneration 

 of the tuber ; second, fungus on the tuber ; third, wet weath- 

 er and generally superabundant moisture ; fourth, Perono- 

 spora infestans attacking the foliage ; fifth, electricity ; and 

 sixth, a plethoric or succulent or diseased condition of the 

 plant caused by specific manures. 



The remedies proposed were : Use of new sorts of potatoes 

 for planting ; steeping or kiln-drying the tubers previous to 

 planting; use of lime as manure; clumping, tumping, or hil- 

 lock-growing ; bending the haulm downward clear of the 

 tubers; tying the haulms upright, and other modifications 

 of the mode of cultivation ; dressing with sulphur, chlorine, 

 etc. ; cutting oif tops on the appearance of the disease; sow- 

 ing disease-proof sorts ; the use of lightning-conductors of 

 various modes of construction ; and the avoidance of the use 

 of certain manures. 



In view of the unsatisfactory results of this competition, the 

 committee have recommended that a sum of money, say 100, 

 be granted for the purpose of inducing a competent mycolo- 

 gist to undertake the investigation of the life-history of the 

 potato fungus (Peronosp>ora infestans), especially in the in- 

 terval between the injury to the potato plant and the reap- 

 pearance of the fungus in the following year; and that a 

 valuable purse be offered, first, for the best disease-proof early 

 potato; and, second, the best disease-proof late potato; and 

 also, for the purpose of encouraging the production of new 

 varieties having the desired qualities, that prizes be offered 

 for disease-proof potatoes of new varieties, to be sent in for 

 competition in 18*78. 



In summing up the present state of our knowledge of this 

 disease, the committee state that the natural history of the 

 potato fungus, from the time it attacks the foliage until the 

 potatoes are harvested, is now well known, but that we are 

 entirely ignorant of what becomes of the parasite from the 

 potato harvest until its reappearance the following year; 

 therefore the latter portion of its history offers a suitable 

 field for investigation. 



