The HOLOSTIGMAT LENS 



IS THE BEST 



for 

 Instantaneous 

 Photography >«r- 



Gives perfect definition over the whole plate at full aperture, and 

 3rields crisp negatives entirely free from haze and false reflections. 



These conditions can only be obtained in Lenses which consist of 

 Cemented components. 



The Holostigmat is made with cemented components, 



LENS LIST SENT POST FREE. 



W. WATSON & SONS, LTD., 313, High Holborn, London . 



THE BRITISH WARBLERS 



A HISTORY WITH PROBLEMS 

 OF THEIR LIVES 



BY 



H. ELIOT HOWARD. F.Z.S.. M.B.O.U. 



To be completed in 9 parts. Size, Imperial 8vo. Price to Subscribers, 21/- per part 



net Parts 1 to 6 now ready. Containing 27 Coloured and 39 Photosrravure Plates, 



8 Maps of Distribution and 280 pases of letterpress. 



To be published in 10 parts. 8vo., each containing 1 2 

 or more Coloured Plates, at 10s. 6d. per part net. 



THE EGGS OF EUROPEAN BIRDS 



BY THE 



Rev. FRANCIS C. R. JOURDAIN. M.A., M.B.O.U. 



Parts 1-4 ready, with 320 paces of text and 52 coloured plates. 



R. H. PORTER, 



7 PRINCES STREET, CAVENDISH SQUARE, LONDON, W. 



