X LIST OF ILLUSTRATIONS. 



FIGURES IN THE T^EXT—contifmed. 



Page 132, 134, and 135. Three forms of two-speed Fine Adjustments. 

 „ 151. Section of double-image colour disc. 



„ 156. Two views of a new form of forceps for holding cover glasses. 

 „ 192 and 193. Spermatozoon of the Rat. 

 „ 210. The Protractor-apertometer. 

 „ 255. Myrotrichvm uncinaf us &nd Aseobolus immersus. 

 „ 257. Syncephalls intermedia and Oedocephalum glomerulosum. 

 ,, 25S. Magnusia yiitida and Spnmatoria longicollis. 

 „ 262. Diagrammatic representation of different appearances of black 



and white dots on Diatom valves. 

 „ 302 and 305. Diagrams illustrating the production of black and white 



dots on Diatom valves. 

 ,, 308. Diagrammatic representation of the variations of the critical 



angles, etc., according to the medium in which Diatoms are 



mounted. 

 „ 317. Cyvibdlopora bulloides. 

 „ 332. Diagram representing the production of an image by an optical 



system. 

 „ 335, 337, and 338. Diagrams in connection with the description of 



Cheshire's Condenser- Scale Apertometer. 

 „ 350. Diagram illustrating the use of Abbe's Apertometer. 

 „ 353. A simple form of reflecting polariser. 

 „ 393. Method of cutting a fly's proboscis to show the teeth. 

 „ 394. Teeth of various flies. 



,, 419. Pinnnlaria ohlonga, P. majo7; and Cymhella cusjjidata. 

 „ 422. Xavicnla cusjudata, and chromatophores of Sv.rirella calcarata. 

 „ 464. Water-mite larva from the stomach of a trout. 

 „ 500, 502, and 503. Diagrams illustrating various forms of pocket 



magnifiers. 

 „ 549. Metallurgical stage for ordinary microscopes. 



