Fig. 8. Nematode Root Knot. 



a. Root knot of Irish potato, b. root knot of onion, c. root knot of parsnip, d. 

 egg of nematode, Heterodera radicicola, e. young female worm, /. half-grown female 

 worm, g. young male worm, h. matured male worm ready to emerge from old body 

 covering, i. matured female worm (d, to '. greatly enlarged, after Stone and Smith). 



