Abstract
1. A new method of separating the cone cells and colored oil globules from the cone retina of a tortoise is reported.
2. The extract of isolated cone cells of the tortoise is observed to show a difference in the spectrum with three maxima in 650 mμ(red), 560mμ(yellow green) and480mμ(blue). But these maxima are inconstant.
3. The change of spectral absorption of the alcohol or digitonin extract of colored oil globules due to illumination coincides with that of the extract of cone cells in yellow green, and blue spectral ranges.
4. The presence of vitamin A2 in the cone retina of a tortoise can not be demonstrated, owing to the interference of the colored oil globules.
