KOOT-KNOT EELWOKM. 231 



practicable) rate of outlay, to have eluded the most careful 

 research. Some good it is considered may be done in special 

 growing (as where one kind of crop can be kept thoroughly in 

 hand, in limited space, or under glass, or in pots), by use of 

 what are called trap-plants. That is, by sowing some small 

 crop which is an object of attraction to the Eelworms, such 

 especially as Lettuce ("Salat," Lactuca sativa), and keeping 

 watch on these until it is found that galls are forming on the 

 roots, then removing them, and destroying them with the 

 contained pests. But in this treatment the utmost care must 

 be taken in removal of the " trap-plants," for if they are 

 draicii from the soil, however carefully, some of the galls, and 

 with them the Eelworm tenants, will be likely to remain 

 behind. 



From his various records of observation Dr. Neal (in his 

 work previously quoted) gives a summary of methods by which 

 the disease can be easily introduced into areas not previously 

 infested, which is a valuable practical guide as to points to 

 be watched against. He mentions introduction may be "by 

 means (1) of planting infested trees; (2), by the use of com- 

 posts of muck and weeds from infested soils ; (3), by the 

 distributive action of water and air, the water carrying 

 particles of soil and worms downward from an infested 

 elevation, or by dry soil, fragments of dry roots"; and he 

 also notes, "(4) soil containing these worms, I have no doubt, 

 has been carried on the feet of men and animals, and de- 

 posited in healthy fields, forming the nucleus of a destructive 

 agency, months afterwards made visible by its effects." — 

 (J. C. N.) 



To the above notes, taken from Dr. Neal's useful observa- 

 tions, should be added, in regard to the last item as to methods 

 of transportation, — carriage in soil adhering to agricultural 

 or garden implements, as ploughs, spades, forks, or trowels, 

 or on wheels of carts or wheelbarrows. Also (most especially) 

 care should be given in infested nurseries, or, in our country, 

 in hothouses, or in growing of crops, such as Cucumbers, 

 Melons, or Tomatoes under glass, that all earth in pots, or 

 boxes, where infested plants have grown should be burnt, and 

 the pots, or boxes, well scalded. If the earth, or the f/allcd 

 roots, are merely thrown to the rubbish heap, there is no limit to 

 the mischief that mat/ be done ; even by the carriage of the 

 wormlets about the place on the feet or feathers of birds, cats, 

 dogs, or other creatures. 



In the paper on this Nematode by Dr. J. Eitzema Bos,* he 

 mentions that "the ground in which the Boot Eelworms have 



* ' Tierische Schadlinge und Niitzlinge,' von Dr. J. Ritzema Bos, p. 781. 



