Eat the ones with the black seeds, your kids will be able to have kids, what do you think the gmo is doing to the watermelon, it is rending all of its kids infertile. The chemical they put on the watermelon plants will give you cancer as well -A Farmer
I don't experiment that but I also read some articles about watermelons like without any seeds inside in it causes some kinds of diseases for everyone so if we change the nature It will definitely give some side effects and I think this will be the reason for that