xvni. ] EAR-COCKLE IN WHEAT, OATS, & RYE. 109 



The small purplish -black grain -like growths found 

 within the flowering glume and pales in the disease known 

 as ear-cockle, are galls caused by the attack of a nematoid 

 or thread -worm, named, by Dr. H. C. Bastian, Tylenchus 

 tritici. Tylenchus is a compound word derived from the 

 Greek, and indicates the knoblike growth of the galls and 

 -the so-called "spear" of the Nematode that is, the mus- 

 cular bag forming the back part of the mouth; tritici, of 

 course, refers to the classical name of the wheat plant. 

 The popular names ear-cockle, purples, and peppercorn 

 have reference to the form, size, and colour of the little 

 galls ; these galls are roughly comparable, on a small 



X 2 



FIG. 44. 



Spikelet of Wheat, the grains replaced by the galls of Ear-Cockle. 

 Twice the size of nature. 



scale, with the familiar galls found on the leaves of the 

 oak and other plants. The Nematode itself is a close 

 ally of the well-known " eels " of stale paste and vinegar. 

 In a Nematode-infested wheat spikelet, such as the one 

 illustrated at Fig. 44, the little blackish galls or pepper- 

 corns can generally be seen as illustrated between the ill- 

 grown glumes and pales. Four of these galls are shown 

 free at Fig. 45, A, B, 0, and D, enlarged five diameters. 

 These galls are commonly two bodies conjoined, seldom a 

 single body, and in rare instances three conjoined bodies, 

 always within the pale and flowering glume. For the 

 reason that the galls are commonly two conjoined bodies 



