THE DEVELOPMENT OF PHOTOPIC AND SCOTOPIC VISION IN THE FROG (RANA TEMPORARIA),
Abstract
The development of photopic and scotopic vision in the frog (R((Rana temporaria) was investigated, using the electroretinogram as an index of visual function. It was found that very young tadpoles always showed the spectral sensitivity typical of cone function, maximal at approximately 570 millimicrons, irrespective of their state of light-adaptation. As the tadpoles grew older the Purkinje shift developed progressively, only becoming complete after metamorphosis. This confirms the previous behavioural experiments of Birukow (1949). The results indicate that the lack of a Purkinje shift in young tadpoles is not due to the rods being non-functional, but is a consequence of the rods having a spectral sensitivity at this stage of development which is the same as that typically associated with cones. It is concluded that the rods develop through a cone-like stage, both in their histological appearance and in their spectral sensitivity. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 07, 1963
- Accession Number
- AD0612563
Entities
People
- W. R. A. Muntz
Organizations
- University of Oxford