I20 Journal of Agricultural Research voi. vi.No.s 



more vigorous until finally they ruptured the shells and emerged, after 

 which the egg walls collapsed. Occasionally a young nematode hatched 

 within the body of a dead female. In cultures the eggs hatched in 

 from 30 to 32 hours from the time of deposition, and the nematodes 

 matured in from 7 to 10 days. The males appeared to mature slightly in 

 advance of the females. 



At hatching, the young nematodes were about 0.2 mm. in length (fig. 

 I, D), very slender, and sluggish, and remained for a time in a curled 

 position. Later they straightened out their bodies and became very 

 active. The young worms were almost transparent (in water cultures), 

 there being no solid food in the alimentary canal. As development pro- 

 ceeded, the young became darker in color and more active. At the end 

 of 5 days the sex organs began to appear, and in from 7 to 10 days the 

 nematodes reached maturity. 



Specimens which were isolated and kept under observation were noted 

 to molt at least three times, these molts occurring about three days apart. 

 The process of molting (fig. i , E) was as follows : The nematode first fas- 

 tened its posterior end to any surface upon which it might be resting. 

 The skin then broke at the anterior end and the nematode began to 

 emerge. At first the process was very slow, owing to the fact that the 

 opening of the molt skin was smaller in diameter than the middle part of 

 the body. By moving vigorously from side to side, the nematode slowly 

 worked its way out of the skin. After the widest portion of the body 

 had passed through the opening, no further resistance to emergence was 

 offered, as the posterior end rapidly decreased in diameter. The nema- 

 todes were not always able to emerge, as occasionally specimens were 

 found which died before completing the process. Molting lasted from 

 45 minutes to 6 hours. 



The adults and the young were similar in form and food habits, but 

 differed in that the adults possessed sex organs. The mature females 

 were about 0.7 mm. in length and 0.03 mm. in diameter, while the males 

 were about 0.6 mm. in length and 0.02 mm. in diameter. 



As soon as maturity was reached, mating began (fig. i, A). The male 

 fastened its caudal end around the middle of the female's body. During 

 this process the male held its body rigid, while the female moved vigor- 

 ously from side to side. It was not uncommon to find males in the act 

 of mating with their bodies wrapped twice about the females. Toward 

 the end of the process the female increased her activity and soon shook 

 the male free. Many matings were observed, the shortest of w^hich 

 lasted about 2 minutes and the longest 30 minutes. 



Proportion of sexes. — Of 367 specimens examined, 229 were found 

 to be females and 138 were males. In other cultures in which counts were 

 not made the females were noticed to be more abundant than the males. 



