164 



Biology in America 



brought us so many wonderful messages from Mars, is located 

 near its southern base. The mountain, 12,794 feet in height, 

 marks the grave of an extinct volcano, and several lesser vol- 

 canic peaks rise from the plateau near the main peak. 



If we reverse the usual order of things and fancy ourselves 

 deposited by aeroplane on the summit of the peak we shall 

 find ourselves in a treeless, wind swept area of "bare vol- 



AN ALPINE DWARF 



At 13,000 feet on Pike's Peak, Colorado. From " Plant Indicators." 

 Courtesy of Doctor F. E. Clements and the Carnegie Institution. 



canic rock," which even in this southern latitude (35N.) is 

 snow-clad for three-fourths of the year. Here many of the 

 herbs tend to form spreading rosettes, their leaves keeping 

 close to the earth, and sending up a short flower stalk from 

 the center. In the intense sunlight of the clear mountain 

 air, growth is rapid and flowers and fruits mature early. 

 To paraphrase an old saw the plants make fruit while the 

 sun shines. Most of them are species occurring on high moun- 



