138 



MISSOURI BOTANICAL GARDEN. 



of the 10th it rained more or less constantly, and when the 

 bags were examined, at eight o'clock the next morning, a 



It remained cloudy, with 



found in bag no. 1. 



little or no rain, until nearly eleven o'clock, when a lively rain 



set in. 



An examination of both bags at this time showed 



that no more larvae had come out. About one o'clock, 

 it cleared up somewhat and four more larvae were found 



in bag no. 1, and eighteen in bag no. 2. 



It rained fre- 



quently during the afternoon and following night. At five 

 o'clock in the afternoon, four more larvae were in bag no. 

 2, and at eight o'clock the next morning, 

 more had dropped in the same bag. These were the last 



still eighteen 



ones caught, though the bags were left in place until 

 the seed pods split open. Two larvae were seen to 

 leave the pods, and this was while it was raining. These 

 dropped quickly down at the end of a silken thread. 



These observations show, therefore, that it is during rainy 

 weather, when the ground is softened and consequently 

 easily penetrable, that the larvae make their escape from 

 the capsules and enter the soil ; and it is of interest to note 

 that they do this either during the daytime or at night, 

 and not exclusively toward the end of the night, as Pro- 

 fessor Riley had predicted.* The use of a thread, sup- 

 porting the larva in its descent, is in accordance with the 

 prediction of Professor Riley, t who, since the preceding 

 observations were communicated to him, expresses the 

 opinion that the larvae may descend both by use of a 

 thread and by crawling, as does the codlin of the apple. 



* Third Garden Report, 114. 

 t I. c. 114. 



