312 Report of the Consulting Entomologist for 1886. 
Fig. l.—Oat-JPlant 
with " Tulip-root " 
disease. 
extent at various places in Mid-Lothian and Linlithgowshire, 
and in the shires of Lanark, Renfrew, and Aberdeen ; more 
southerly, it has occurred in Yorkshire, and has also injured 
young winter oats at a locality in Berkshire. The diseased 
plants may usually be known by the swollen tulip-like base of 
the stem, and the numerous pale, stunted, and crumpled up shoots 
surrounding it ; but in diseased plants, which have attained 
maturity, I have not found the pale side shoots, and in very 
young infested plants I only found a swollen 
gall growth, which, conjecturally, presently 
increases into the diseased swelling known 
as " tulip-root." 
I found the Anguillulidse, or nematode 
worms, commonly known as " eel-worms," 
which are considered (and I believe) to 
cause this disease in great numbers in the 
brown, crumbly, and decaying matter inside 
the swollen base of the oat - plants, also 
sometimes within the sheathing-leaves, and 
likewise within the contorted side shoots. 
Eggs also were sometimes present. From 
the excessive minuteness of these thread- 
worms it is not yet clearly ascertained, as 
far as I am aware, which species causes 
the oat disease in this country. It has been 
considered that the Heterodera (? Tglenchus) radicicola may be 
the special kind. I find that the injuries described as following 
on presence of the Tylenchus dipsaci, Kuhn., in corn, correspond 
with our oat attack, but whether more kinds than one are 
present, or whether one kind may not pass under several names, 
is not as yet clearly ascertained. 
In regard to prevention, it has been recorded that the genus 
Tylenchi have enormously prolonged living powers, and ^in the 
case of the Tylenchus tritici, which produces wheat-ear cockle, 
the wormlets have been found by the late Dr. Cobbold to have 
a power of existing for four or even five years. Much longer 
periods are assigned by other observers. This points directly 
to the importance, when once a crop is infested, of not again 
putting that crop in till there is reasonable cause to suppose the 
land is clear. 
In consequence of it being considered that the attack followed 
beans, I examined for " eel-worms " in various parts of bean- 
stumps and roots, but found no trace of these. Ill several 
instances the attack has occurred after turnips, and I have 
received a plan of infested fields, in which the diseased portion 
was limited to a long strip, in one instance across, and in 
