WORMS. 225 



known as "peppercorns" and "purples." In several 

 parts of the ear short thick dark-brown galls (Fig. 

 133), resembling the seeds of corn-cockle, are found 

 instead of wheat grains. Inside the thick brown 

 shell there is a yellowish-white mass, containing 

 hundreds or even thousands of eelworm larvae (one 

 thirty-first to one twenty-seventh of an inch long). 

 These are quite dry and rigid, but gradually revive 

 on moistening, even if the black galls have remained 

 twenty years in the dried- 

 up condition. When the 

 wheat is ripe the dark- 

 walled galls are gathered in 

 with the crop, and in many 



cases are sown again with Fig. 133.— Ear cookies of wheat ; the 

 the sound grains. The tMrdshowstheeelwormlarv^eonits 



brown shell then decays, and 



the eelworm larvse leave the gall, travelling to a 

 neighbouring wheat seedling, where they live between 

 leaf sheath and haulm, also penetrating into the 

 terminal bud. The haulm of a wheat plant infested 

 by many eelworms remains relatively short, the leaves 

 are often sharply bent and have wavy margins. 

 Wheat plants thus infested closely resemble rye 

 plants diseased in a similar way, but are much less 

 deformed. This is because the wheat eelworms do 

 not reproduce tiU they reach the ear, and there is 

 consequently only one generation per year, while 

 several generations of eelworms succeed one another 

 in the same rye plant. The eelworms quickly travel 

 from all parts of the plants into the ears, and get into 

 the rudiments of the flowers, causing them to swell 

 up like bladders, and their walls to become first dark 

 green, and then dark brown. Sixteen to twenty 

 eelworms are present in the lowest flowers of the 

 ear, ten to twelve in those higher up (and therefore 

 smaller), and four to six in the topmost (smallest) 

 ones. Soon after entering the flowers the eelworms 



