Fig. 3
From: Also looking like Limulus? – retinula axons and visual neuropils of Amblypygi (whip spiders)
Cobalt fills via median eyes in Amblypygi. Phrynus marginemaculatus; sagittal sections (a-c); frontal sections (d-f). a, b, Two consecutive sections of the same specimen. a, First and second median eye visual neuropil filled with cobalt. Note dense arrangement of Cobalt-filled profiles in the first visual neuropil and just a few filled fibres running further to the second visual neuropil resulting in a diffuse staining of the neuropil. Both neuropils are connected via a tract (arrow). Bar 100 μm. b, First and second visual neuropil stained. Additionally, a thin tract connects the second median eye neuropil and the second lateral eye neuropil (arrowhead). A few cobalt filled R-cell axons run through this tract and terminate in the second lateral eye neuropil. Bar 100 μm. c, Same situation in a different specimen. Some cobalt filled R-cells from the median eye terminate in the second lateral eye visual neuropil. Bars 100 μm. d-f, Same situation in a third specimen and in frontal sections. Bars 100 μm. M1, first median eye visual neuropil; M2, second median eye visual neuropil; L1, first lateral eye neuropil; L2, second lateral eye neuropil; arrow, tract connecting M1 and M2; arrowhead thin tract connecting M2 and L2