230 MASSACHUSETTS HORTICULTURAL SOCIETY. 



The Committee on Publication Iiave mueli pleasure in adding to 

 the Transactions the following paper, kindly offered to the 

 Society by the author : 



Notes on the FrN(;L"s Causing Damping Off, and Other 

 Allied Forms. 



By Thomas Walton Galloway, Marshall, Mo. 



I. Damping Off. — The damping off fungus has been known 

 for a number of years through its disastrous effects upon seed- 

 lings. The peculiarities of the disease and the approved methods 

 of treating it have been described by several contributors — 

 gardenei'S and botanists — in the "American Garden," June, 1890. 

 A more extended account is to be found in "Diseases of Plants," 

 by H. Marshall Ward. In these papers various opinions are 

 given with regard to the probable botanical character of the plant 

 or plants causing the malady, some of the writers regarding it 

 not as the work of a parasite but as the direct result of certain 

 conditions of moisture and temperature ; others deeming that the 

 disease is caused by a growth of algae about the subterranean 

 portion of the plant, resulting in a suspension of the functions of 

 the roots, and a consequent destruction of the seedling. 



Notwithstanding the frequency of its occurrence in greenhouses 

 and plant beds where seedlings are grown, there is the greatest 

 latitude among gardeners concerning the application of the term. 

 Many apply it to any conspicuous mycelium which ma}' grow over 

 the sand and weaker seedlings, without any reference to the effect 

 produced b}' it. Others use the term in a much more restricted 

 sense, distinguishing by it certain manifestations of disease on the 

 part of the seedling, rather than any external fungous growth. 

 This is the interpretation given b}' the most careful gardeners with 

 Avhom I have talked, and is the one which I shall adopt in my 

 study of the disease. 



The behavior of seedlings suffering from an attack of damping 

 off presents the advantage of being very characteristic, and when 

 once seen may always be recognized. Its first appearance is 

 indicated by a slight paleness and drooping of the seedlings. If 

 these be carefully removed, it will be seen that the root, either 

 throughout its length or in portions, is beginning to shrink and 



