Cucumbers - C. sativus
Melons - C. melo
...Armenian cucumbers - C. melo
Some melons, Cucumis melo L., resemble cucumbers, being elongate and used as vegetables when young, fresh or pickled. However, C. sativus and C. melo differ from one another in some vegetative traits, plant sexuality and various fruit characteristics.
...
Plant sexuality differs between the two species, however. Plants of C. sativus become increasingly pistillate as they develop (Shifriss, 1961). In sharp contrast, plants of C. melo bear pistillate or hermaphroditic flowers only on the first one or two nodes of shoots, and all apical nodes are staminate (Rosa, 1924). Theophrastus wrote: Some flowers are sterile, as in sikyon, those which grow at the ends of the shoot, and that is why men pluck them off, for they hinder the growth of the sikyoi. The sterile flowers, of course, allude to the staminate flowers and, according to the description, these are borne on the shoot ends, which are nipped off. Removal of the shoot apices would encourage the development of new shoots, pistillate flowers and fruits.
https://aob.oxfordjournals.org/content/109/1/117.full

The above bit was interesting. As soon as it's light enough, I'm going to go out and see if I can spot these differences. Also, maybe I should try pruning the melon vines as described.
