784 



LIGHT AND LIFE 



.0 - 



o 

 o 



> 



z 



LJ 



> 



< 

 _l 

 UJ 



o: 



0.5 



300 400 500 600 my/ 



Fig. 4. The spectral sen.sitivities of the several receptor systems described for the 

 honeybee (broken curves) and a visual pigment from the bee (.solid curve). 1, The 

 .spectral sensitivity of the dark-adapted compound eye of the worker bee. Maxi- 

 mum, .53.5 m;x. From (20). 2, The ultraviolet receptor svstem of the compound 

 eye of the worker bee as revealed during adaptation with a bright yellow-green 

 light. The maximum lies near 345 m^. A receptor with similar spectral sensi- 

 tivity is foimd in the compoimd eye of the drone and the ocellus of the worker. 

 From (20). 3, .Spectral sensitivity of the compoimd eyes of drones. The maximum 

 is at about 440 m/^; however, as other preparations may be more sensitive at longer 

 wavelengths, there is evidence that a green-sensitive receptor (curve 1) is also con- 

 tributing to this curve. After (19). ■/, The 490 ni/x receptor of the ocellus of the 

 worker bee. -\fter (23). 5, The absorption spectrum of the light-sensitive retinene- 

 protein pigment extracted from the heads of honeybees, (.\fter 18 and 19). 



violet adapting light lowers the sensitivity of both systems (20) . 

 There is some evidence that a similar situation prevails in the eye of 

 the cockroach (56, 57, 58) . 



In the compound eye of the worker honeybee there is thus evi- 

 dence for two of the three color receptors postulated by Daumer. 

 There is at this time no conclusive electrophysiological evidence to 

 indicate the existence of a blue-violet receptor in the compound eye 

 of the worker. However, two additional sets of observations suggest 

 that a blue-violet receptor may be present. 



In addition to the two receptor systems described for the worker 

 bee, the compound eye of the drone appears to possess a receptor 

 system maximally sensitive at about 440 ni/x (19) . The contributions 

 of the several receptors to the spectral sensitivity function of the drone 

 vary in different preparations, probably depending on the composition 



