Vl PREFACE. 



emy of Science, Salem, Mass.; by the publishers of the 

 American Naturalist, and by the Boston Society of Natural 

 History, while forty of the cuts of birds have been electro- 

 typed from the originals of Cones' Key, and Tenney's Zoology. 



Measurements are usually given in the metric system ; in 

 such cases the approximate equivalent in inches and fractions 

 of an inch being added in parenthesis. 



Should this manual aid in the work of education, stimu- 

 late students to test the statements presented in it by person- 

 al observations, and thus elicit some degree of the inde- 

 pendence and self-reliance characteristic of the original in- 

 vestigator, and also lead them to entertain broad views in 

 biology, and to sympathize with the more advanced and 

 more natural ideas now taught by the leading biologists 

 of our time, the author will feel more than repaid. 



BROWN UNIVERSITY, 



Providence, B. I., October 25, 1879. 



PREFACE TO THE SECOND EDITION. 



A NUMBER of changes have been made since the first edi- 

 tion, consisting either of the correction of errors, or the 

 insertion of facts new to science since the book was written. 

 Figures of the opossum and its marsupial bone have been 

 inserted on p. 575, and improved illustrations have taken 

 the place of Figs. 400 and 492. The author would be 

 thankful for the communication of additional errata, and 

 for suggestions from teachers tending towards the improve- 

 ment of the book ; and here acknowledges, with thanks, 

 kind aid from several naturalists in revising the first edition. 



July, 1880. 



