How can i teach my babay pigeon to eat by its own?

i have a 40 days old babay pigeon its parents abanded it when a crow attacked its nest and took away one babay pigeon it was only 10 days old since i am feeding and taking care of it i give it seeds which i gve to my lovebirds 4 times a day and i used to give it water through syringe but now it knows how to drink water by itself but it still does not know how to eat by itself when i keep bowl full of seeds it trys to eat but it is not able to eat it then then it looks at me and cries for food so i open its mouth and feed it so how can i teach it to eat by itself and i read somewhere that pigeon should be given small stones so that it can digest its food so can i give any stone from my garden please help