北京萤火虫复眼的光学成像*

本文利用光学成像方法，研究了不同适应状态下的北京萤火虫phrococelia Pekininsis复眼所成的光学重叠像以及复眼的视场角。不同适应状态的晶体柱都能在距离复眼表面300-350μm之处形成光学重叠像。经过暗适应的晶体柱可以对不同物距的目标形成清晰的正重叠像，像的大小随物距的增大而减小；经明适应的晶体柱，成像物距范围变小，重叠像的像面亮度降低；经过漂白处理的晶体柱只能对一定的物距成像，像面亮度最低。 不同数目的晶体柱都能形成一重叠像，并随着其数目的增加，像面亮度也逐渐增强。根据对局部复眼视场范围的观察和其结构特征的了解，认为萤火虫单个复眼的视场角大于180度。

THE OPTICAL IMAGING OF COMPOUND EYE OF BEIJING FIREFLY PHROCOCELIA PEKINENSIS

The, optical superposition images and field angle of the compound eye of Beijing firefly Phrococella pekinensis was observed by means of optical imaging under different adaptation states. Crystalling cones could form a real superposition image at a distance of 300-350 m from the surface of cornea (correspond to the level of retina) under different adaptation states. A real optical superposition image was formed by dark-adapted crystalline cones for an ob-ject at different distances and its size decreased as the object distance increased. For the light-adapted crystalline cones the range of object distance became smaller and the brightness of superposition image became lower than they were with dark-adapted crystalline cones. Bleached crystalline cones could form a superposition image only at a certain distance and the brightness of image was lowest in the three cases. Diiferen; number of crystalline cones could form the same superposition image but the increase in image sharpness arose from the increase in number of the crystalline cones. According to the observation in the field of part of the compound eye and the characteristics of its structure, the field angle of the compound eye of the Beijing firefly was found to be over 180