STdDIKS IN THE RETINA. 23 



Studies in the Retina: Rods and Cones in the 

 Frog and in some other Amphibia. 



By 



II. M. Beiiiai-d, M.A.Caiitab. 



(From tlie Biological Laboratories of I he Koyal College of Science.) 



VVitJi Plate 3. 



Part I. 



A CLOSE comparative study of Vertebrate retinas, even 

 though comprehending less than twenty species, threatens to 

 be a veiy prolonged undertaking. It is therefore proposed 

 to publish an account of certain new anatomical facts which 

 can be dealt with separately. Such a publication is not 

 exposed to the same objections as can be legitimately made 

 against the ordinary " preliminary notice of results." It 

 will not, of course, be possible to treat the new facts quite 

 without reference to the new points of vieAV to which the 

 researches are tending. It may, indeed, be necessary at the 

 end to sketch some of these very briefly, trusting that no 

 long interval will elapse before the evidence on which they 

 are based can be published. 



It is, first of all, a pleasant duty to preface this communi- 

 cation by acknowledging my debt to my friend Mr. Martin 

 Woodward, of this College. His great knowledge of zoology, 

 and especially of modern technical methods, has been 

 placed most unreservedly and generously at my disposal. 

 While the pursuance of the work and its responsibility are 

 mine, any permanent additions to knowledge which may 

 result from it must be largely credited to him, as the 

 technical work in connection with these researchen has been 



