18 
BEANS. 
viz., that where the Beans are affected they followed Oats last year, 
and that the evil ceases immediately where Barley was grown last 
harvest. There is still another mystery; 
the four rows (shown hy dotted lines) by 
the side of the injured Beans are quite 
perfect, and Barley grew in 1889 hy the 
Barley 
in 
1889. 
(All Rye-grass 
in 1890.) 
Oats 1889. 
Beans 
affected, 
1890. 
Barley, 1889. 
Beans good, 
1890. 
side of these. I suggested to the bailiff 
whether the Beans were planted exactly 
at the boundary of the Oats, or whether 
they encroached somewhat on the Bar¬ 
ley stubble ; but he speaks with great 
confidence that this was not the case.” 
On examining the Bean stems I found Eelworms present in the 
rough or powdery matter within. These were few in number, and at 
first appeared, excepting in one doubtful instance, to be dead, or at 
least wholly motionless. After soaking in water, however, one 
became active, and I could clearly distinguish a spear with a bulbous 
base, and, so far as I could ascertain, it was the species Tylenchus 
devast atrix. 
As it was very important to be quite certain as to the nature of the 
Eelworms, both with regard to damage to the Bean crops, and also 
with regard to rotation of crops on infested land, I forwarded specimens 
to the skilled examination of Dr. J. Ritzema Bos, of Wageningen, 
Holland, who wrote me as follows :— 
“ I examined the Bean stems, and, exactly as you wrote to me, I 
found in the inner blackish mass a great number of Eelworms. They 
were all in a lethargic condition. By damping them in water most of 
them recovered. The earliest were a pair of Eelworms without a 
spear. The next—or, at least, almost the next—to revive slowly had 
all a spear, and all the characteristics of Tylenchus devastatrix .” 
Dr. Ritzema Bos further added that all the reviving Eelworms were 
larvae, and all possessed a spear, but that in this genus of Nematodes 
we cannot quite completely determine the species whilst they are still 
in larval state. He further added that amongst the crumpled-together 
Nematodes which had not revived he found one female which possessed 
a spear, which, it was tolerably apparent, was T. devastatrix , for the 
absolute and relative measurements agreed with those of females of 
this species ; but up to this date no males were noticeable, which are 
needed for right determination of the species. Therefore I sent a 
further supply of diseased Bean plants, in which, as will be seen by 
the report of Dr. Ritzema Bos, given after my own description and 
measurements of these diseased plants immediately following, the male 
was present, and thus (through the skilled examination we were 
favoured with) we have certain knowledge of the presence of the 
