DISTRIBUTION OF SPORES AND SEEDS. 2/1 



movements, brought about by variations in light and tem- 

 perature, which act as stimuli. (See ^f 244.) 



II. Adaptation to distribution of spores. 



The fact that spores are found in every group of plants 

 from the lowest to the highest makes it probable that a great 



B A B 



Fig. 233. Fig. 234. 



F[G. 233. — A, flower of Califomia poppy {Esckscholtztn), opened in sunshine ; B, the 



same, closed in wet weather. Natuial size. — After Kerher. 

 Fig 234. — A, aerial liypha of Piiabolus crystnllinus, with, spore case. The hypha is 

 swollen beneath the spore case and very turgid. By the same witli spore case torn 

 off at base and being; shot away by the violent escape of the mucilaginous contents of 

 the hypha. Magnified about 10 diam. — After Kerner. 



variety of ways will have been adopted by plants to secure 

 their distribution. The more important ways may be grouped 

 as follows : 



384. I. By turgor and tension.^Among the fungi, spores 

 are often forced out of the spore case by the pressure upon 



