Transparencies 

 at the left oj the 

 Orizaba group. 



Boreal Zone 

 Timberline, 

 alt. 13,000 ft. 



Boreal Zone 

 Pines and 

 Spruces, alt. 

 9500 ft. 



Temperate 

 Zone 

 Clearings, alt. 

 5000 ft. 



Tropical Zone 

 Rio Blanc a, 

 alt. 1000 ft. 



some time in preparation, but it is 

 well worth waiting for. From the 

 upper side of a gorge through which 

 runs the Rio Blanca, the observer 

 gazes through the vine-hung tropical 

 forest to where Mount Orizaba bathed 

 in sunlight rises, more than 18,000 

 feet, its head crowned with perpetual 

 snow. 



In the foreground are tropical 

 birds — motmots which swing their 

 tails like pendulums, trogons, parrots, 

 tanagers and big-beaked toucans, 

 while here and there humming birds 

 hover over rare orchids. On either 

 side of the group is a series of trans- 

 parencies, showing how the character 

 of the country changes as one goes 

 upward from the plain, passing 

 through the dense forest to the barren 

 higher levels of the mountain and its 

 top capped with snow. As Mr. 

 Chapman tells us in the label, we 

 have here a section of country more 

 than three miles high and to find on a 

 level the changes to be met with in 

 these three miles we would have to 

 journey from Vera Cruz to Maine, 

 a distance of three thousand miles. 



The background is by Robert 

 Bruce Horsfall, the birds by Henry C. 

 Raven, while the accessories were 

 made by and under the supervision 

 of William Peters by whom the whole 

 was assembled. 



The Orizaba group has been made 

 possible through the North American 

 Ornithology Fund, and the Museum's 

 indebtedness is acknowledged to those 

 contributors to this fund whose gen- 

 erous support for several years has 

 brought into existence some of the 

 best in the series of bird habitat 

 groups. These benefactors of the 



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