j *@ - Sociedade Brasileira de Psicologia

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(1976) >ed the spectral flash method, and one of us (Fietz et al. 1986) med the
spectral sœn method in order to determine the sensitivity as accurately as m ssible.
The peak sensitivities were found to be at 3351m , 435nm and 540nm ; the functional
side band sensitivities originate from the j-absorption of the respective rhodopsin.
Autrum & v.zwehl (1964) reported two kinds of blue receptors, one absorbing
maximally at 420nm and the other at 470nm . Although in the meanwilile we have
recorded from many receptor cells, we have not found any indication of more than
one blue receptor.
The spectral receptor types were mnrked intracellulary with Porcion yellow
(Menzel & Blakers, 1976). Each median frontal ommatidilxm contains two long and
one proximal Uv-cells, two blue œlls, and four green cells. lhe Uv