INTRODUCTION. 



As this little book is intended to be no more than an 

 introduction to an agreeable branch of microscopical study, 

 it is to be hoped it will not require a formal preface ; but 

 a few words may be convenient to indicate its scope and 

 purpose. 



The common experience of all microscopists confirms the 

 assertion made by Dr. G-oring, that the most fascinating 

 objects are living creatures of sufficient dimensions to be 

 easily understood with moderate magnification; and in no 

 way can objects of this description be so readily obtained, 

 as by devoting an occasional hour to the examination of the 

 little ponds which are accessible from almost any situation. 

 A complete volume of pond lore would not only be a bulky 

 book — much bigger than the aldermanic tomes which it is 

 the fashion to call " Manuals," although the great stone 

 fists in the British Museum would be required to grasp 

 them comfortably, — but its composition would overtask all 

 the philosophers of our day. In good truth, a tea-spoonful 

 of water from a prolific locality often contains a variety of 

 living forms, every one of which demands a profound 

 and patient study, if we would know but a few things 

 concerning it. 



To man, then, is a vast and a minute. Our minds ache 

 at the contemplation of astronomical immensities, and we 

 are apt to see the boundless only in prodigious masses, 



