1062 
Journal of Agricultural Research 
Vol. XXVIII, No. 11 
In August, 1923, chrysanthemum and Phlox drummondii from Washington, 
submitted by Florence Hedges, were found infested by Aphelenchus ritzema-bosi, 
as were also chrysanthemums sent later from Quaker Neck, Chestertown, Md. 
The chrysanthemums showed lesions similar to those mentioned by Osterwalder 
( 14 ), that is, the leaves partly yellow, or yellow and brown. The phlox leaves 
were mostly dried or yellow, very few being green. Nemas were numerous in 
the chrysanthemum leaves, but few in the phlox, where they were found in the 
leaf blades and stem. Although there are Aphelenchi said to infest different 
plants, some closely related to, some synonymous with ritzema-bosi , comparative 
examination of many specimens from all these host plants is necessary before a 
final conclusion is reached. Opinion on the views of Ritzema-Bos (17), Mar- 
cinowski (9), Molz (12), Schwartz (19), Stewart (21) and Goodey (6) on the tax¬ 
onomic position of these nemas is, therefore, withheld. 
The species here mentioned most closely resembles A. ritzema-bosi Schwartz, 
hitherto known only from chrysanthemums. As Goodey recently stated (6), 
this form is undoubtedly synonymous with Stewart’s A. phyllophagus; also the 
specimens from South Africa mentioned by Sandground (18) as A . phyllophagus 
Stewart, belong to A. ritzema-bosi. 
In August, 1923, Dr. Sandground sent the writer A. ritzema-bosi in dried chrys¬ 
anthemum leaves kept since February, 1921. They were partly revived in water. 
Only larval specimens of the stage before the last moult revived , the first specimens 
reviving after 18 hours and soon moulting. The present species, therefore, can 
stand desiccation for at least 22 months. When again dried for from 2 to 5 
weeks, they revived once more in a much shorter time —10 to 12 hours. Speci¬ 
mens which moulted after 22 months of dormancy withstood afterwards a dry¬ 
ing of 3 weeks in the adult stage. 
The specimens from Washington and Chestertown had fine annules and two 
sublateral wings on each side. The head seen laterally was similar to that 
drawn by Schwartz (19, p. 312, fig. 12). The excretory pore, on which Stewart 
lays much stress (21), was rather variable in position; in some specimens scarcely 
the length of the oesophageal bulb behind this latter and rather in front of the 
nerve-ring; in others, well behind the nerve-ring. The male tail end resembles 
that figured and described by Schwartz (19) and Stewart (21) for A. ritzema-bosi, 
except some specimens that show a papilla near the middle of the ventral side 
and just in front of the very end (PI. 2, B). In other specimens this papilla was 
scarcely seen or not at all; in which case no true papilla was formed, but only a 
fine tube. It is uncertain whether this was the outlet of a gland, no glandular 
cells being seen to be connected with it. Therefore, it is believed that the 
present species has really two ventro-median postanal papillae in the male, the 
most inconspicuous one being near the tail end. In some specimens the papillae 
are easily seen with only a low magnification, and at first the writer thought it 
to be A. helophitus de Man as figured by Kati Marcinowski (9). Plate 2, B 
shows a lateral view of such a male tail end. The writer has no additional infor¬ 
mation as to the effect on the host. The observation of former investigators 
that the nemas leave the plants when put in water can be confirmed. 
REMARKS ON DORYLAIMUS REGIUS DE MAN AND ITS FOOD 
Rather large-sized species of the nema family Dorylaimidae are numerous in 
most soils; hence the question of their economic significance and relationship 
arises. On account of the spear-like onchium and sucking apparatus, a more 
or less parasitic relationship to plants has been pointed out by investigators. 
In common with various other nematologists, the writer has observed Dorylaimi 
with green intestinal contents, in certain cases recognizable as chlorophyll. 
