PKEFACE. Vii 



and the Andes. We have given but two chapters on 

 the Amazons, for the wonders of that river have been 

 made known bj such writers as Agassiz, "Wallace, and 

 Bates, and many earlier travellers, and to these writers 

 we would refer those of our readers who may desire a 

 better knowledge of the valley of the Great River. 

 The desire of many that a complete narrative of the 

 expedition from our college should be given in a per- 

 manent form, and our own -wish that 'others miglit 

 share with us the pleasure we experienced in viewing 

 a tropical JSTature in those equatorial regions where she 

 presents herself in forms so strange and grand, coupled 

 with the fact that so little has been written upon those 

 interesting portions of the continent to which sections 

 our work is principally devoted, are the only considera- 

 tions that could have led us to undertake the preparation 

 of the present volume. We are conscious that our work 

 has all the imperfections incident to a first effort, and 

 that its kind reception can come only through the kindly 

 indulgence of our readers. 



The illustrations which embellish tlie work are prin- 

 cipally from our own sketch-book, and are, for the most 

 part, representations of natural scenery. In this con- 

 nection we would express our especial indebtedness to 

 Miss F. A. Snyder, to whom our sketches were submit- 

 ted to be prepared for the engraver. 



The expedition is under deep indebtedness to the 

 Smithsonian Institution, which provided instruments 

 for making meteorological observations, and secured 

 transportation of collections, besides giving essential 

 aid in other ways. 



We desire to express our kindest thanks to Dr. Asa 

 Gray, for the identification of many of our plants ; to 



