98 



Plant Physiology 



occur during a cool afternoon or evening of a warm day, 

 and quite commonly in the cool early morning after a hot day 



[Photograph by Russell and Harding.] 



FIG. 30. Destruction of cabbages by Pseudomonas campestris, a germ 

 entering through the water-pores. 



which has served to heat up the soil to a considerable depth. 



The continuous water connection between the tissues 



and the external atmosphere established through guttation 



