I know this is some pretty serious "bringing a thread back from the dead", but since I'M not the one that did it, per se...anyway, I lived in the South Texas Brush Country as a kid and I killed my fair share of rattlers. Also lost a really nice dog to a rattler bite. I managed to kill one pregnant rattler out of all of them. It had quite a few babies inside, but they weren't as developed as these. We thought it had eaten something and wanted to see what it was, so we cut it open...and found something similar to those pics. A lot of folks don't realize that rattlers even have live young, as most snakes lay eggs. I try to leave the vast majority of snakes alone, but I admit (probably due to losing that dog) that I have a severe dislike of rattlesnakes even though I know how many vermin they must kill.
“If you don’t read the newspaper, you’re uninformed; if you do read the newspaper, you’re misinformed“.---Mark Twain