ROOT-KNOT EELWORM. 



61 



it troubles us most in this country), the infested gall-growths may be 

 found from a quarter of an inch over, to masses of confluent galls from 

 one to two, or three and a half inches in length, and about half an 

 inch in breadth. On a single plant as many as twenty of the main 

 roots may be found galled, and these as they branched and branched 



Heterodkra radicicola. — 1, larva ; 2 and 3, females ; 4 and 5, eggs in different 

 stages of development : all enormously magnified. (2) from sketch by Ed. ; the 

 other figures after Prof. Geo. Atkinson. 



again, and even the small side-fibres, were to be found loaded with the 

 irregularly formed soft lumpy galls. 



This attack has been entered on in such great detail in my two 

 preceding Keports that it is unnecessary to repeat the observations 

 here, more especially as we seem still in ignorance of any application 

 which can be brought to bear satisfactorily on it as a distinct remedy. 

 As yet we do not know it in this country as a field attack. 



Any really practicable measures of prevention and remedy which 

 might be trusted to, to answer at a paying rate are greatly needed, for 

 the reports sent duriug the past season show this infestation to be very 

 firmly established in various localities as an attack to Tomatoes and 

 Cucumbers under glass, and is a serious cause of loss. This, like the 

 H. scliachtii, also attacks various out-of-door crops, but we do not as 

 yet appear to have it on them here. 



Those who wish to study the history of this Eelworm both practi- 

 cally and with profound scientific detail, and full illustration, will find 

 these, and also very many tides of publications on Nematode life and 

 history, in the works noted below.''' 



* ' Preliminary Report upon the Life-history and Metamorphoses of a Root-gall 

 Nematode Heterodera radicicola (Greef.), Mull.' Science Contribution from the 

 Agricultural Experimental Station, Auburn, Alabama, U.S.A., 1889. Useful infor- 

 mation is also given in ' The Root-knot Disease,' by Dr. J, C. Ncal, Government 

 Printing Ofiice, Washington, U.S.A., 1889. 



