A. M. Taylor 265 



For the purposes of observation branches of black currant, the buds 

 of which contained worms, were taken directly from the infected 

 tree and hung up in the laboratory without being allowed to come 

 into contact with the soil, from which medium infection from free- 

 living species might occur. The branches were allowed to remain 

 in a dry state for periods of 9 months, 6 months and 6 weeks 

 respectively, at the end of which time microscopic examination of 

 the worms thus treated took place. The worms upon which such 

 enforced desiccation and starvation were thrust were found in all 

 cases to have collected in colonies among the bud leaves in the manner 

 described in the general life history. These colonies in their dry, quies- 

 cent condition were then transferred to a drop of water on a slide and 

 the movements of the individuals thus placed in a medium in which 

 activity could be resumed were observed under a microscope. 



It has been previously shewn in the general life history that the 

 worms in a state of quiescence adopt a coiled position within the 

 colonies. 



On being immersed in water a gradual uncoiling is seen to take 

 place among them, until the body resumes its extended position and 

 the body contents, which during desiccation recede from the epidermal 

 cell wall, return to their normal position. These processes appear 

 to occupy a length of time varying with the duration of the desiccation 

 period. Thus the body contents of the worms which had remained 

 in a state of quiescence for 9 months resumed their normal position 

 against the epidermal cell wall after a period of 30 minutes' immersion. 

 A further period of 30 minutes was however necessary before the worm 

 became indistinguishable in appearance from specimens taken directly 

 from the field. The extended position of the body was not general 

 among the worms until a period of 5 hours follo^ving immersion had 

 elapsed. Movements during this time were frequent among the 

 nematodes, but they were of an irregular and spasmodic nature and 

 were probably due to the expansion of the tissues and not to any 

 voluntary muscular effort on the part of the worm. Following a 

 period of from 20 — 30 hours of immersion a state of progressive activity 

 could be distinguished among the worms under observation. This 

 type of movement was exhibited by an extremely limited number 

 and was characterized by incessant and ceaseless forward motion. 

 Indeed, so swift and rapid were the movements of the active worms 

 that it was impossible to determine their sex until they became weakened 

 and their movements were consequently slower. This intense activity 



