62 MINUTE MARVELS OF NATURE 



spongy cellular arrangement, which serves to 

 evaporate superfluous water, and so keeps up 



Fig. 41. Part of a section througli tlie blade uf tlie sunflower leaf, 

 showing many-celled hairs 



the circulation. Finally, the under-surface of the 

 leaf, consisting of another epidermal layer of 



