EELWOKMS. 



83 



The Beet Eelworm (Heterodera schacMii). 



For some time the beet crop on the Continent has been 

 seriously interfered with by a peculiar rotting disease, which 

 has been shown to be due entirely to the working of an eel- 

 worm, Heterodera schacMii. The female (fig. 33, a) is found 



k 



Fig. 33. — The Beet EniuV/O'Ki.i {Heterodera schacMU). 

 A, female ; e, larva ; c, rootlet with galls (d). (All greatly enlarged.) 



fixed to the root and rootlets of the beet, and, unlike most 

 Anguillulidse, it is citron-shaped, and seldom longer than ir\th 

 of an inch : she nevertheless contains as many as three or four 

 hundred ova. The ova when laid are found in groups, being 

 united by a kind of gelatinous sac. The majority of eggs 

 develop inside the female, this process, as a rule, causing her 

 speedy death. 



