. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 402 A. B. LALL AND T. W. CRONIN Or* Q _l O ui cr i t- i o 420nm 560nm. 0 5 10 15 20 25 30 TIME IN THE DARK (minutes) FIGURE 2. Dark-adaptation of the purple land crab compound eye measured at two wavelengths. The curves tended to be hyperbolic initially and follow a similar time course. Dark-adaptation Figure 2 shows the time course of dark-adaptation measured at two wavelengths (560 nm and 420 nm). The eye was light adapted for 1 minute with white light, and then the responses during dark-adaptation were tested alternately
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 402 A. B. LALL AND T. W. CRONIN Or* Q _l O ui cr i t- i o 420nm 560nm. 0 5 10 15 20 25 30 TIME IN THE DARK (minutes) FIGURE 2. Dark-adaptation of the purple land crab compound eye measured at two wavelengths. The curves tended to be hyperbolic initially and follow a similar time course. Dark-adaptation Figure 2 shows the time course of dark-adaptation measured at two wavelengths (560 nm and 420 nm). The eye was light adapted for 1 minute with white light, and then the responses during dark-adaptation were tested alternately at 560 nm and 420 nm. Initially the threshold decreased hyperbolically, and then after about 20 minutes the threshold decrease was linear. These two curves are parallel, showing that the eye maintains constant relative sensitivities to the two wavelengths throughout dark adaptation. Spectral sensitivity Figure 3 shows the S(X) functions under dark- and chromatic adaptation condi- tions in G. lateralis. The dark-adapted S(X) curves showed a very broad sensitivity in the blue-green (440-520 nm) region of the spectrum. In two animals (A, Fig. 3), the sensitivity in the blue (430-460 nm) region was pronounced. Under chromatic adaptation conditions with both Corning glass niters and narrow band interference niters, the S(X) curves exhibited a decrease in sensitivity of about to log units, but a distinctive and pronounced selective effect with differential suppression of different parts of the spectrum was not observed. The chromatic adaptation curves tended to be broad and rather flat across the spectrum (compare curves a, b, and d for different chromatic adaptation conditions in Fig. 3), except for a small hump in the blue under red selective adaptation light. However, it should be noted that the ERG is a gross response from the whole eye, and chromatic adaptation experiments may poorly separate different receptor types even when the receptors are as far apart in the spectr
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
