ABSTRACT
Micro-and ultrastructure of the photoreceptors and first visual ganglion in the different regions of the compound eye of the wild male and female housefly, and the projections of the photoreceptor cells within the subsequent visual centers have been studied. The morphology of the retina and lamina ganglia in the front dorsal and the equatorial regions of the male compound eye and the front ventral region of the female one, and the projections of the retina within the lamina show the sexspecific characteristics underlying the function of chasing behavior in the housefly.
ABSTRACT
1. The central retinular cells R_7 in the compound eye of male housefly can be divided into two types which are called here R_(7a) and R_(7b) respectively. R_(7a) approximate many features of R_(1-6) cells, which have a larger, cell body, rhabdomere and axon, terminate in the first optic neuropil (lamina). R_(7b) approximate many features of R_8 cell and project directly to the second optic neuropil (medulla). 2. The central retinular cell R_(7a) in the compound eye of male housefly distribute mainly the dorsal region of the eye, there are a few of R_(7a) in the ventral region of the eye, which only distribute in the first and second row ommatidia under equatorial line, but not found in the compound eye of female housefly.
ABSTRACT
The changes of the ultrastructure of the photoreceptors in the compound eye of horsefly (Tabanus mandarinus) were observed electromicroscopically at both the mid-day and mid-night. We found that there were various structural changes in cones, pigment cells, retinula cells, rhabdomeres at the two different times.The functional significance of the day and night changes of the photoreceptors and their relations to natural light illumination were discussed.