114 JOURNAL OF THE 



a very slender cilium or hair-like process. After a time it loses 

 this cilium and then the plastic bit of protoplasm moves slowly 

 about in the damp soil by a streaming movement in various direc- 

 tions. It is capable of streaming out in such very fine threads 

 as to enter the roots of the cabbage along with watery solutions 

 of nutriment. Once within the root it locates in a cell and com- 

 mences to appropriate the living matter of the root to itself. In 

 this way it grows in size, still remaining a very plastic body of 

 simple protoplasm. Thousands of these enter the roots of a 

 single cabbage. Not only do they appropriate to themselves the 

 living matter of the root, but they cause the root of the cabbage 

 to produce an increased number of cells, so that oval or fusiform 

 enlargements are formed. The cells of the rijot iu which these 

 parasitic masses of protoplasm are se.ited increase greatly in size 

 compared with those which do not contain the parasite. The 

 Plasmodium, for so this mass of protoplasm is called, is yellow- 

 ish in color. Late in the season it divides up into countless 

 minute bits of protoplasm, each of which secretes a protective 

 wall about itself, and its life cycle is completed. The diseased 

 cabbages become sickly, turn yellowish and either die or do not 

 head. 



Now in external appearance these enlargements of the roots, 

 which are called "club-foot,'' very much resemble the enlarge- 

 ments called root-galls, which are })roduccd by the nematode. 

 Unless one was pretty certain of the locality from which the dis- 

 eased S{)ecimens came and knew the history of the disease in that 

 locality it would be venturesome to undertake to say whether it 

 was root-gall or ''club-foot" until after a microscopic exami- 

 nation of the parasite or of the structural characteristics of the 

 diseased root. 



I have some very fine specimens of ^'club-foot" before me 

 which I obtained from Eastern North Carolina nearly a year 

 ago. Having been placed in strong alcohol the enlargements 

 are a little wrinkled and shriveled. But so closely do they 

 resemble, especially in a fresh condition, the root-galls that when 

 I collected specimens of cabbages here this autinnn with enlarge- 



