3° 



age to other well known greenhouse plants such as coleus, spinach, 

 heliotrope, fern, moon flower, begonia,* and clematis.'' 



Halsted'' has also called attention to the occurrence of nematodes 

 in the leaves of coleus, chrysanthemum, lantana, bouvardia, begonia, 

 pelargonium, salvia, zinnia and ficus comosa, where they give rise to 

 decomposed spots in the leaves which finally result in their falling 

 ofT, and giving the plant a generally unhealthy appearance. Hal- 

 sted has also observed them in the oat in New Jersey, and Sturgis* 

 has found them doing considerable harm on the roots of outdoor 

 asters. From the large list of plants attacked by nematodes belong- 

 ing to numerous and widely separated families it would seem that 

 almost every family under peculiar circumstances might be subject 

 to them. Nematodes normally have a choice in their host, but when 

 this is not present they will attack other plants which apparently 

 seem uncongenial to them. Instances have come under our obser- 

 vation where a crop of lettuce which had been preceded by a crop 

 of nematode infested cucumbers was profusely covered with nematode 

 galls. This, however, in our experience is exceedingly unusual 

 although we are aware of the fact that Kiihn gives the lettuce in 

 Germany as one of their host plants. We have, however, grown 

 many crops of lettuce in infested soil without ever finding a gall 

 upon their roots. 



Amount of Damage Caused by Nematodes. 



When we take into consideration the large number of host plants 

 subject to nematode attack and the economic value of these plants, 

 the losses caused by them must be enormous. The losses, however, 

 are much more severe in those countries where the winter is mild 

 than in colder climates where the nematodes are practically confined 

 to greenhouses. In Europe the greatest loss occurs to sugar beets 

 and in our Southern States the damage done to all kinds of fruit 

 trees and garden truck amounts to considerable. In regard to the 

 extent of the losses caused by nematodes to our economic plants we 

 can do no better than quote Dr. N. A. Cobb, (1. c, p. 179) Patholo- 



2. Selby, Ohio Agr'l Exp. Station, Bull. 73, p. 22S. 



3. Comstock. Garden and Forest, Vol. III., p. 59. 



4. N. J. Agr'l Exp. Station, Fifth Annual Rept., 1S92. p. 385. See also Garden and For- 

 est, Vol. III. and IV. 



5. Conn. Agr'l Exp. Station Report. 1892, p. 45. 



