VI CONTENTS. 



PART No. 51, NOVEMBER 1902. 

 Papers. 



PAGE 



J. Rheinbeeg, F.R.M.S. The Black aud White Dot Phenomenon 



(Illustrated) 301 



A. Earlaxd. On Cymhalopora lulloides (^d'Orbigny) (Plate 16) . 309 



W. Wesche, F.R.M.S. Observations on Male Rotifers (Plates 17 



and 18) 323 



F. J. Cheshire. Simple Methods of Focometry and Apertometry 



(Illustrated) 331 



J. B. SCRIVEN. The Preparation of Serial Sections of Insects . . 343 



Notes. 



F. J. Cheshire. A Method of Using Abbe's Apertometer (Illustrated) 349 



F. J. Cheshire. A Simple Form of Reflecting Polariser (Illustrated) 353 



G. Massee, F.L.S. On Chaetommni Ijostrycholdes .... 355 

 Mutual Help in Microscopical "Work ....... 357 



Reviews. 



Notices of MiQUEL & Cambier's" Traite de Bact^riologie " ; Massee's 

 " European Fungus Flora-Agaricaceae"; Bausch's "Manipulation 

 of the Microscope " ; Martin Duncan's " First Steps in Photo- 

 Micrography " ; Petit & Borne's " Manuel pratique de Bacterio- 

 logie "; and HiORNS's " Metallography " 361 



Proceedings, etc. 



Proceedings from March 21st to June 20th, 1902, inclusive . . . 369 

 Objects Exhibited, with Notes. March to September, 1902 . . 381 



PART No. 52, APRIL 1903. 



Papers. 



W. H. Harris. The Dentition of the Diptera (Plate 19) . . . 389 

 T. B. ROSSETER, F.R.M.S. On the Anatomy of Brepanidotaenia 



tenuirostris (Plate 20) 399 



W. Ayrton. On Zoothanmium geniculatum, n. sp. (Plate 21) . . 407 

 W. Wesche, F.R.M.S. The Male Organs of Scatophafja lutaria and 



S. stercoraria. (Plate 22) 411 



F. R. Rowley, F-R.M.S. Some Points in the Structure and Life- 

 History of Diatoms (Plate 23) 417 



