CONTENTS. 



Page 

 Preface 9 



CHAPTER I. 



Introductory Remarks on the Application of the Micro- 

 scope to the Sciences, with an Account of its recent 

 Improvements 17 



CHAPTER II. 



On the Larva and Pupa of a Straw-coloured Plumed Culex 

 or Gnat 5O 



CHAPTER III. 

 On the Larva and Crysalis of a Day-Fly 61 



CHAPTER IV. 

 On the Larva of a Species of British Hydrophilus 70 



CHAPTER V. 



On the Terms employed in Microscopic Science 



With a Description of the Vertical Microscope 79 



