106 
APPENDIX. 
Eelworms. Tylenchus devastatrix, Kuhn. 
(Continued from page 47.) 
“Tulip-root” in Oats. 
In the case of Tulip-root attack it is of great importance to know 
what is the precise kind of Eel worm which causes the disease, because, 
as previously mentioned (p. 37), there are some kinds which are so 
very long-lived that they may remain in the land for years, and thus 
be ready to infest any crop put in that may suit them. 
It is now in my power, through the able assistance most kindly 
granted me, to state that the kind of Eelworm present in specimens of 
our English Tulip-root disease in Oat plants has been found to be the 
TyJmclms devastatrix of Kuhn, formerly known as the Tylenchus dipsaci, 
Kuhn, but of which it was considered desirable to change the special 
name, on account of the variety of crops which it has been found to 
devastate or greatly injure, instead of being more particularly hurtful 
(as was formerly supposed) to the Teazel [Dipsacus fuUonum), whence 
its specific name of dipsaci. 
I beg to acknowledge with many thanks my obligation for the 
following notes to the information kindly given me by the eminently 
well-skilled observers, Dr. J. G. de Man, Middleburg, Netherlands, late 
Conservator of the Museum, Leyden ; * and Dr. J. Ritzema Bos, Pro¬ 
fessor of Zoology at the Agricultural College, Wageningen, Netherlands, 
who has studied this Eelworm disease for many years, and has written 
upon the subject, with valuable details of his own experiments, and is 
shortly about to publish a Monograph on this and on other species of 
Eelworms {Nematodes) injurious to crops. 
It appears that this disease was first observed on Rye, and the 
name of Stock-krankheit, or more shortly “Stock” (which may be 
translated stem-sickness, or more shortly the “ Stem”) was bestowed 
upon it; and afterwards the same species of Eelworm was found to 
cause the “ Stem” also in Oat plants. The above term draws attention 
much in the same way as our own term of Tulip-root to the nature of 
the attack affecting the development of the stem. As in the middle 
of the winter there is much difficulty in procuring fresh specimens, I 
could only offer for investigation young plants of winter Oats from the 
infested field, mentioned at p. 43, and also some stubble from the 
field marked 1886 in the plan given at p. 42 ; but although the 
diseased growth was only just slightly showing as yet in the former. 
Dr. Ritzema Bos found therein specimens which he determined as 
being certainly the Tylenchus devastatrix^ Kuhn, a few of them being 
fully developed. 
* Author of the work on Anguillulidae, entitled, ‘ Die frei in der reinen erde und 
in sussen wasser lebenden Nematoden der Niederlandischen Fauna.’ 34 plates. 
