59 



vicinity of Minnehaha (altitude 8,000 feet) consists principally 

 of Pseudotsiiga taxifolia and Picea Engelmanni. The former 

 predominates at lower, the latter at higher elevations. Such 

 forests may become quite mesophytic and are best developed on 



Fig, 2. I. p. E. on dunes at Sawyer, Michigan. From left to light : (stand- 

 ing) Dr. Brockmann-Jerosch, Dr. E. N. Transeau, Professor H. C. Cowles, Pro- 

 fessor O. W. Caldwell, Mr. A. G. Tansley, Dr. O. Paulsen, Mrs. A. G. Tansley, 

 Professor C. Schroter, Professor A. Dachnowski, Professor J. M. Coulter, Mrs. H. 

 Brockmann-Jerosch, Professor T. J. Stomps. Professor C. von Tubeuf ; (seated) 

 Dr. G. D. Fuller, Dr. E. Rubel. Top branches of dune-buried oaks in background. 



north slopes. South slopes, on the other hand, are usually cov- 

 ered with a more xerophytic, open type of forest in which Pinus 

 ponderosa scopiiloruni and Pinus flexilis are the characteristic 

 trees. Gravel slides in all stages of forestation are a prominent 

 feature in the neighborhood of Minnehaha.* The day selected 

 for the ascent of Pikes Peak was cold, wet and disagreeable, 



* See Schneider, E. C. The distribution of woody plants in the Pikes Peak 

 region. Colorado Coll. Publ., Science Ser. 12: 137-170. Map. 1909. Also the 

 succession of plant life on the gravel slides in the vicinity of Pikes Peak, loc. cit., 

 12: 289-311. fig. 1-6. 1911. 



