You have to learn how to hunt the crystal lizards better. Once a lizards is killed or disappears it won't respawn, unless you beat a boss in the archstone level you are in. That sets the lizards respawn count up +1. A good way to hunt lizards is with a theif ring, and a strong bow like a compound long bow +10, and a peircing weapon like a winged spear +10. Hold it with both hands, run up to the lizard and attack, usually the first strike (if it's not a running strike) will miss, but the second one will hit and kill it. If you google demons souls items and find the wiki site, you can learn everything you wanna know about demons souls there. That web site helped me get a platinum in demons souls.