June 14,1924 
Plant Parasitic Nemos and Related Forms 
1061 
ledge which soon tapers and nearly disappears springs from the cephalated part 
and perhaps forms either the edge of a membranous, wing-like, lateral part of the 
spicula, or the cutinized part where the very inconspicuous and weakly developed 
protractores spiculorum are attached (PI. 1, N). The copulatory muscles are 
indistinct and the details of the bursal muscles doubtful, a result of the small 
number of muscular fibrils, rather than absence of the muscles. As to the 
papillae typical of male Cephalobi, the present material shows much variation in 
number and location (PI. 1, I, J, K, L, and M). The European Cephalobus 
elongatus De Man is, as Cobb remarked, perhaps identical with the present form; 
but it differs in the pharynx [see descriptions by De Man (7) and Marcinowski 
(8)] in the position of the papillae of the male; and also the position of the 
excretory pore is much farther cephalad. De Man (7) shows the gubernaculum 
of elongatus linear, states its great variability, but omits morphological details. 
Thus the relationship of the two forms is uncertain, but the variability, with 
transgressional characters of both, suggests identity. The following formulae 
indicate much variation in the length of the individuals and of the organs: 
female ^0.935 (0.7-1.4)mm. (11 specimens measured). 
male 
1.1 15. 20. 'M 94.1 
1.3 3.1 3.3 3.5 2.7 0,863 
Females 
a-21.9 (19.6 -29.4 )] 
0- 4^8 ( 4. 34- 5.88) n-11. 
*—15.1 (11. 8 -25l 0 )J 
(0.74-1.08)mm. (9 specimens measured). 
Males 
a—28. 0 (27.0-29. 4)1 
0- 4.9 ( 4.6- 5.1) in-9. 
*-11.2(14.9-20.0)1 
The largest specimens were from cultures on concave slides in a drop of water 
containing parts of grains, leaves, and stalks of corn (Zea mays); various other 
plant materials were also used with success. 
Cobb succeeded in rearing subelongatus in macerated silage; in this case cock¬ 
roach meat was also used, both foods being productive of good results. Sube¬ 
longatus may therefore be regarded as omnivorous and well fitted for varied life 
conditions. More attention should be given to the ability of the genus Cephalobus 
to enter and live in healthy plants; hitherto the inclination has been to disregard 
Cephalobi as the cause of injury to plants. 
KIGELIA PINNATA, THE AFRICAN SAUSAGE TREE, AS A HOST PLANT 
OF HETERODERA RADICICOLA 
A knowledge of plants subject to root-knot, caused by H. radicicola, is of 
importance to horticulture, agriculture, and forestry. 
Kigelia pinnata , the sausage tree, must be added to the list of host plants of 
H. radicicola , since young plants, apparently soil-infested, raised from seed and 
brought by Mr. Woods of the inspection office of the Federal Horticultural 
Board, showed attacks of this parasite. It may also be noted that snapdragon 
(Anthirrhinum majus) plants from Washington, D. C., were badly infested by 
H . radicicola. 
REMARKS ON THE CHRYSANTHEMUM NEMA, APHELENCHUS RITZEMA- 
BOSI SCHWARTZ, AND ITS PRESENCE IN THE UNITED STATES 
The presence of this nema pest in the United States has not yet been definitely 
established. Atkinson (I), mentioned an Aphelenchus sp. causing disease in 
chrysanthemum buds from Baltimore, Md. 
