xvrii.] EAR-COCKLE IN WHEAT, OATS, & RYE. 113 



resuming activity after remaining dormant for twenty- 

 seven years. 



Various observers have artificially infected wheat with 

 the Tylenchus by placing the living Nematodes taken from 

 a gall in the furrow or cleft of the grain, and then planting 

 the infected seeds in the soil in the usual manner. Or galls 

 may be planted in close contiguity with healthy grain ; 

 after a brief time the Nematodes will work their way 

 through the wall of the softened and decaying galls, and 

 come naturally in contact with the young leaves sprouting 

 from the healthy seed. The Nematodes then insert them- 

 selves between the sheaths of the leaves, gradually working 

 their way round till they come to the innermost, where 

 they remain till the rudiments of the future ear begin to 

 form. Several grasses, in addition to wheat, oats, and 

 rye, are assailed by Nematodes, notably Festuca elatior, L., 

 maize, and different species of bent grass, Agrostis. 



Other Nematodes attack cucumbers, melons, carnations, 

 and many different plants belonging to our greenhouses 

 and flower and kitchen-gardens. These have never been 

 scientifically described by zoologists, or even named. 

 Sometimes the Nematodes attack the roots, especially the 

 rootlets, and they cause little nutlike swellings to appear. 

 Sometimes the stem, and in other instances the leaves, are 

 made the point of attack, and the Nematodes cause dead 

 pallid patches to appear. On cutting a slice from a pallid 

 spot, or a slice from a nodule belonging to a rootlet, the 

 Nematodes and their eggs are almost invariably met with. 

 The worms are coiled in various ways within the eggs, and 

 after a definite period the eggs burst, and the young 

 thread-worms emerge. 



As it has been clearly proved that ear-cockle can be 

 produced by planting the galls containing the Nematodes 

 with sound grain, the greatest care should be taken in 

 separating the galls from the seed-wheat. This should 

 be a very easy matter, as the galls are black in colour, 

 whilst the grain is yellow, and the galls are only one-half 

 I 



