I can't remember what temps corn eggs need because I only have BPs and boas, but if you hold a flash light to the eggs you can do what is called candling. Good eggs will be red/pink and show veins, some maybe yellowish but still have veins and bad eggs (slugs) won't have any veins. Corns don't do maternal incubation so you will need to do it yourself or find someone to incubate them for you.