IV 
PREFACE. 
mented by museums, monographs, and microscopes. Nat¬ 
ural History has outgrown the limits of a single book. 
TriaLhas proved the folly of giving the student so many 
things to learn that he has no time to understand, and the 
error of condemning the student to expend his strength 
upon the details of classification, which may change in 
the coming decade, instead of upon structure, w T hich is 
permanent. Of course, specialists will miss many things, 
and find abundant room for criticism in what they regard 
as deficiencies; but the work should be judged by what 
it does contain, rather than by what it does not. 
What is claimed, in the language of inventors, is the 
selection and arrangement of essential principles and 
typical illustrations from the standpoint of the teacher. 
The synthetic method is employed, as being the most 
natural: to begin with complex Man, instead of the sim¬ 
plest forms, would give a false idea. Man is not a model, 
but a monstrosity, the most modified of Vertebrates. 
But these outlines must be filled up, on the part of the 
teacher, by lectures, and by the exhibition of specimens; 
and, on the part of the student, by observation (noting, 
above all, the characteristic habits of animals), and by per¬ 
sonal work with the knife and microscope. No text-book 
can take the place of nature, or supersede oral instruction 
from a competent teacher. 
Suggestions and corrections from naturalists and teach¬ 
ers will be thankfully received. 
In a work of this character, which is but a compound 
of the labors of all naturalists, it w r ould be superfluous to 
make acknowledgments. The works referred to on page 
397 have been specially consulted. 
