June, 1915.J 
Root-knot or Eelworm Attacks. 
553 
for the most part had decayed, liberating the eggs and egg-filled 
bodies of the female nematodes into the soil. The tops of the 
tomato plants and as many of the remaining roots as could be 
found, were removed from the bench. The soil itself, however, 
was not given a soil treatment, but was allowed to remain in an 
infested state. 
The foreman in charge of the greenhouses gave directions to 
place various potted bedding plants on top of this bench, allowing 
the pots to come in direct contact with the soil which had previous¬ 
ly grown the infested tomato crop. The experiment proved an 
interesting one, for among the potted plants there were a number 
which became infested, while, on the other hand, a few kinds 
which were under the same environmental conditions proved 
non-susceptible to an attack. 
After having stood on top of this bench for more than a month, 
the following plants showed the development of nodules upon their 
roots, and upon a microscopic examination revealed the egg-filled 
nematodes of Heterodera radicicola: Vinca rosea Linn. (Mada¬ 
gascar Periwinkle), Chrysanthemum frutescens Linn. (Mar¬ 
guerite), Celosia empress (Cockscomb), Matthiola incana Var. 
annua Voss. (Ten-weeks or Intermediate stocks), Zese mayz (Bur¬ 
bank’s Rainbow Corn), and Phlox (Phlox annual). The writer 
also reported Cirsium arvense (Canada thistle), a susceptible 
host (Science, 40::241, 1914). There were also a large number of 
other plants whuch were attacked, but only those which proved 
to be new hosts have been listed here. 
The eelworm has been previously reported as attacking 
Zeae mayz by Neal, B. P. I. (1889), Burbank’s Rainbow corn 
being a horticultural variety of Zeae mayz. 
The following is a list of potted plants which remained ap¬ 
parently unaffected, although they were growing among the in¬ 
fested potted plants: Centaurea imperialis (Royal Sweet Sultan), 
Calundula (Pot marigold, Vaughan’s Mammoth Mixture and 
Eldorado), Salvia Zurich (Dwarf Sage), and Canna varieties. 
The soil which was used in the bench was originally obtained 
from a nearby orchard, and was probably infested with Heterodera 
radicicola at the time that it was placed in the greenhouse bench, 
although it is possible, but not probable, that the organisms 
gained entrance through the application of infested manure; 
knowing the source of the fertilizer used, this did not appear to be 
the case. The soils in many sections of Kansas are badly infested 
with the eelworm, and the problem of economically combating 
this pest is becoming a serious problem, especially in the truck¬ 
growing regions where entire crops become affected. 
Besides the above hosts, the writer obtained specimens of 
Carum petroselinum (parsley) from Hutchinson, Kansas, which 
