PREFACE 
THERE are many good books on Zoology, or Nat- 
ural History, as it is commonly termed; but none are 
properly adapted to instruction in schools. Some of 
them are too popular in their character, and some, on 
the other hand, are too scientific, or, rather, contain 
too many of the details of science; while in all there 
is too much matter, so that the pupil is confused with 
the multitude of things brought to view, and there- 
fore obtains definite ideas of but few of them. I have 
aimed in this book to avoid these defects. My object 
has been to cull out from the immense mass of mate- 
rial which Zoology presents that which every well-in- 
formed person ought to know, excluding all which is 
of interest and value only to those who intend to be 
thorough zoologists. 
It seems to have been forgotten by most writers 
of text-books on the natural sciences that a book for 
common study should be very different from a book 
for reference. Their books are therefore cumbered 
with much that is not of any use to the great body of 
pupils. The true plan for instruction in schools re- 
quires that, while the class-book should contain, 
clearly stated, only that which all ought to know, the 
teacher should have some works on the subject of a 
more extended character, to which he can refer when- 
ever occasion calls for it. 
A 
