ABBREVIATIONS. 



H. means high power; a combination of lenses such as the 

 i inch objective of an English microscope, with an eye- 

 piece of medium power, or the No. 7 objective and No. 3. 

 eye-piece of Hartnack's microscope-^with the tube of the 

 microscope drawn out magnifying about 300 diameters 

 linear. 



L. means low power ; a combination of lenses such as the 

 i inch objective of an English microscope, with an eye- 

 piece of medium power, or the No. 3 objective and No. 3: 

 eye-piece, of Hartnack's microscope, magnifying about 50 

 diameters. 



V. S., L. S., and T. S., respectively mean vertical, longitudinal, 

 and transverse section. 



