PLANT NEMATODES THE GROWER SHOULD KNOW 43







































 Figure 28.-A and B. Root systems of two dying corn seedlings (Zea mays L.)
heavily attacked by the smooth headed meadow nematode (Pratylenchus leioce-
phalus) (see Fig. 27). These seedlings were collected by R. J. Humphrey near
Sanford, Fla.
 Figure 27.-The smooth headed meadow nematode, Pratylenchus leiocephalus
Steiner, 1949. A. Adult females; x 333. B. Anterior end; note the 3 nuclei of
the oesophageal glands and their arrangement; nrv r, nerve ring; x 500. C. Head
end note the angular outline of the head proper and the 3 basal knobs of the buccal
stylet which are so well amalgamated as to appear as a single spherical knob; x
1222. D. Front view of head; amph, amphid, a chemical sense organ; cph ppl,
cephalic papilla, an organ of touch; X 1222. E. The basal knobs of the buccal
stylet as seen in optical cross section; X 1222. F. Tail end of female, drawing to
show the annulation of the cuticle and its interruption by the lateral field; phas,
phasmid, an outlet of a gland; x 500. G. Tail end: anus; phas, phasmid; vlv, vulva;
note the short postvulvar uterus branch; x 500. H. Tail end in ventral view; anus;
phas, phasmid; vlv, vulva; x 500. I. Egg as it is deposited; note the kidney form
which is characteristic for Pratylenchus eggs; x 500. J. Egg containing larva of
which the pear-shaped end bulb of oesophagus is to be seen; x 500. K. Egg with
larva of which tail end is to be seen; X 500.