CORN. 
than a slight enlargement of the base of the stem, but (as she wrote 
me) some of the leafage had the peculiar plaited appearance at the 
edge which accompanies this attack, and in one case the plant had 
distorted, pale, wrinkled shoots, growing in a knot under the plant 
itself. The sender had reported that the growth appeared quite 
checked. 
“ The examination of these plants proved the complete absence of 
Tylenchus devastatrix; but I discovered in the very first plant 
examined, and then, further, also in the others, the occurrence of 
another species of Eelworm , viz ., of Ceplialobus rigidus, Schneider. 
Similarly to what is the case with T. devastatrix, large numbers of 
individuals of this Ceplialobus , both males and females, adult as well 
as young ones, and also free eggs (some of which contained living 
embryos), were found by me in partly-decayed stems, presenting a 
brownish powdery appearance. In some cases many individuals were 
also observed on the inner surface of the lower sheaths of the leaves. 
The Eelworms evidently lived in these plants quite in the same 
manner, and in the same number of individuals, as does T. devastatrix 
in those plants that are affected by true ‘ Tulip-root.’ As far as I am 
aware, this remarkable fact has hitherto never been observed. 
“ But further, according to my opinion, there can now be little 
doubt that this species ought to be regarded as the cause of the disease 
from which these Oats were suffering, and that, at least in this country, 
Ceplialobus rigidus , Sclm., as well as T. devastatrix , is injurious to the 
Oat-fields. Ceplialobus rigidus, Schn., with which Ceplialobus oxyuris, 
Biitschli, is identical, hitherto was only known as occurring in the soil 
about the rootlets of plants, like the other land nematodes. The 
Ccphalobi may be easily distinguished from the Tylenchi by the absence 
of a knotted spear, and by the oesophagus terminating in a rounded 
swelling (bulbus), containing a simple valvular apparatus. Whereas 
some species of Ceplialobus have a bluntly rounded posterior extremity, 
in C. rigidus it is sharply pointed. This Ceplialobus, therefore, much 
resembles another form of the same genus, that is also very common 
about the rootlets of plants, and which I have described under the 
name of Ceplialobus oxyuroides; but C. rigidus attains a larger size, and 
presents, moreover, some anatomical differences. 
(Signed) “ Dr. J. Of. de Man, 
“ Of Middleburg, Netherlands. 
“ Penzance, July, 1888.” 
The figures on the accompanying Plate will explain the scientific 
terms in Dr. de Man’s description. Fig. 1 shows the female Eelworm, 
of which the natural size is little more than one millimetre (that is, 
little more than one twenty-fourth part of an inch in English 
