“NEMATODE GALLS IN MARKET WHEAT. ~~ _ ane 
and wrinkled. Usually they are shorter and broader than sound 
wheat kernels, but sometimes are equal in size, or again may be very 
narrow and needlelike. Very small galls, the size of wild buckwheat, 
are also found frequently. It is not uncommon to find several of 
them tightly cemented together. 
In color the galls vary from a light gray to a jet black. Usually 
they are dark brown but may also be mottled to some extent. 
The covering of the gall is very thick, making up some 95 per cent 
by weight of the entire gall. It incloses a yellowish-white powdery 
- Fie. 3.—A transverse section of the nematode gall, ahowite worms and 
outer thick husk. X35 
substance, which, when moistened with water and placed under a 
magnifying glass, ‘is seen to disintegrate into small thread-shaped 
worms about two-tenths of an inch in length and two-thousandths 
of an inch in width and slightly decreasing in size at each end. 
Figure 3 is a transverse section of one of the galls magnified to show 
the thick covering and the inner powdery substance composed mostly 
-of small worms. Figure 4 is a photograph of one of the nematodes 
or eel worms highly magnified to show its structure. 
The galls, upon falling to the ground, decay under fdvorable mois- 
ture and temperature conditions. The nematodes then escape, and, 
_17The Bureau of Markets wishes to express its gratitude to, Miss B. H. Silberberg, 
Bureau of Chemistry, for the photomicrographs of figures 3 and 5. 
