PREFACE. 



decade ago, hampered by obsolete text-books and 

 general want of information ; but I have not intended 

 it primarily for scholastic uses. I have had in view, 

 as I have already hinted, the large and, I trust, in- 

 creasing class of adult students who want a iirst 

 lesson-book in a given science, which treats that sub- 

 ject from its very first elements, and yet treats it in a 

 'manner not calculated to draw down upon the' volume 

 and 'its author the remonstrance brought by I)ickens's 

 bricklayer against Mrs. Pardiggle's tract, that " It's a 

 'hooJc fit for a bahhy, and I'm not a hahbij," The com- 

 mercial man, the clerk, and the well-educated artisan 

 "help to make up the class of students I refer to — 

 students whose enthusiasm for knowledge is sUch as 

 ■ to lead them to seek it, self-taught and self-guided, 

 in their short intervals of leisure. 



Many of these isolated and self-taught students of 

 ' Zoology have both rrieans, leisure, and intelligence 

 ' sufficient to enable them to carry on their studies to 

 some purpose, but are wasting their time over obso- 

 lete books and worthless microscope slides, for want 

 of a guide to the whereabouts of knowledge. This 

 want I have endeavoured in some degree to supply. 



B. L. 



