472 



Stem Eelworm. 



been dried up for 2 J years by putting them in water, and 

 he is of opinion that life may continue latent even longer 

 than this. It is apparent that this faculty enormously 

 increases the chances of the distribution and spread of this 

 nematode, which may be carried into fields, market-gardens, 

 allotments, and gardens in this dried up state with manure 

 made from infested straw, in these days cut close to the 

 ground, or with hay composed of the infested clover and 

 grasses taken into yards, stables, and sheep-folds. 



Great cold causes suspended animation in the Tylenchus 

 larvce. Want of food — the absence of food-plants — brings 

 the larvae in the soil up to the surface where life is suspended 

 in the dry soil, in which state no food is required. This 

 eelworm may be conveyed from one field to another on the 

 feet of men (according to Kiihn), horses, and other animals^ 

 also on the wheels of carts, waggons, and barrows, and by 

 the wind on dusty and sandy soil. In the case of onions 

 and flower bulbs, infested pieces of leaves, and bulbs left 

 in fields or gardens, or thrown into refuse-heaps, pigstyes,. 

 and yards, are fertile sources of infestation. In Infested 

 clover-leys ploughed for oats, wheat, or beans, there are 

 always roots containing live eelworms, harrowed up and left 

 on the surface of the ground, which leave the roots when 

 they begin to dry up, or remain in the larval form within 

 them in suspended animation, until mild temperature and 

 moisture revive them, when they forthwith attack the crops 

 near them. The larvae may also be preserved in this form 

 in the stems of wheat, oats, and bean plants, and will be 

 ready to infest any host-plants near when circumstances 

 favour their emergence from a torpid condition. 



As one important means of preventing, or diminishing, the 

 spread of this nematode after infested clover, oat, wheat, and 

 bean crops, the land should be deeply ploughed with a skim 

 coulter affixed to the plough, so that the roots, stubble, and 

 haulm are deeply buried ; those left on the surface should be 

 harrowed together with a fine harrow, taken off the land, 

 and burned. In very bad cases it would be right not to let 

 plants liable to this attack follow infested crops, or to give as 

 long a fallow as possible after the deep ploughing. After 



