Something that came up at work today brought home the similarity of meaning of reticule and graticule, in each case the second meaning is identical, and yet they stem from different Latin words. I wonder how this happened?

Reticule:

French, réticule, L. reticulum, dim. of rete a net.

1. A little bag, originally of network; a woman's workbag, or a little bag to be carried in the hand.
2. A system of wires or lines in the focus of a telescope or other instrument; a reticle


Graticule:

French, from Latin craticula fine latticework, diminutive of cratis wickerwork, hurdle.

1. A grid composed of horizontal and vertical lines printed over an image, such as a map, to assist in locating specific features.
2. A network of fine lines, dots, cross hairs, or wires in the focal plane of the eyepiece of an optical instrument.