ADJUSTMENT TO TEMPERATURE 



133 



is raised. Changes of position are shown in Allium, Campanula 

 Chamcenerium, etc., where the drooping or horizontal flower becomes 

 erect after fertiUzation, largely owing to the action of gravity. 

 The upright position appears to promote the ripening of the fruit 



Fig. 37. Inflorescence of the bluebell, Campanula petiolata, in which the 

 bud is erect, -while the flower and fruit are turned downward by the 

 movement of the pedicel. 



and to place the seeds in a more advantageous position for dis- 

 semination. The elongation of the scape in consequence of 

 growth after flowering, such as occurs in the dandelion and other 

 stemless composites, seems to be for the purpose of lifting the 

 achenes above the surrounding plants, in order to increase the 

 chances that they will be borne away by the wind. 



Experiment 43. Kinds of fruits. Since relatively few fruits mature 

 in the spring, the study of the kinds of fruits and their relation to migra- 

 tion should be made early in the autumn. The number of fruits at this 

 time is very large, and the opportunities for observation unusually 

 favorable. A field trip should be made through prairie and woodland in 

 early fall, the various kinds of fruits noted, and the species grouped 



