Odd Fruit, Protecting Itself

I came across some local persimmons in the grocery today; so I decided to buy one and take it home to see if it had seeds in it that could forecast the winter weather.  A few weeks ago I bought some persimmons from California at Whole Foods, but they turned out to have no seeds.  Barren persimmons, useless for my investigation.  Well, I struck out again.  What's going on with persimmons?  This one was smaller than the California ones, and it was a little softer.  But when I cut it open I saw the same seedless seed places.  I took a bite of this one.  It tasted sweet and juicy at first;  then the inside of my mouth began to feel like it had been spray painted with texture paint.  Who eats persimmons?  Do you have to brine them or something in order to eat them??

Next to the persimmons in the exotic fruit section was this hand-grenade of a fruit.  The sign said simply "horned squash."  The horns were sharp and irregularly distributed over the surface.  I imagined a kind of cantaloup would be inside.  But no-- when I cut it in half this is what was there:  densely packed green seeds surrounded by a little gelatinous green stuff.  There was nothing to eat, unless this fruit is one of those pomegranate  fruits that really don't have much besides the seeds that you suck on and spit out.  I could imagine a colorful but frustrating salad made of pomegranate seeds and horned squash seeds. 

I've read that most plants don't really want to be eaten and have devices to defend themselves and ward off predators such as humans:  spines, bitter taste, hard shells, poison, irritating oils.  This plant makes fruit that is destined to be left alone in peace to ripen its seeds and then release them in time.