TREE FERNS ON MOUNT KENIA 



Tree ferns are seen only at high altitudes-not below seven thousand feet— and only on the 



mountain slopes. They stand some thirty feet high with the undergrowth around them 



matted and dense. Sunlight may filter in. but even so, one full minute's exposure 



is necessary to get a photograph. The elephant avoids tree-fern patches, 



perhaps because they usually grow along the edges of steep ravmes 



172 



