Why are iBooks files not saved on iPad?

Recently due to some update. I've had to have all my iBooks files stored on iCloud or somewhere... (although I know not how to access directly) instead of having them simply saved on the iPad like I put them. So when i'm out and about open up iBooks to look at the files, THEY ARE GONE! And they show a download from the cloud icon instead. Lo and behold I don't have the internet on demand everywhere I go. I can't ACCESS THEM! This has become a problem more times than I can count. I need the files back on the iPad ready and available. Is there ANY way to remedy this awful new design?