Likely a sterile medium means an uncontaminated culture (food free of living organisms) that will grow only the new bacteria introduced for analysis. Source(s): http://www.thefreedictionary.com/sterile
Stonepelt was Bluestar's first mentor and a very well-respected senior warrior of ThunderClan. It is revealed in this book that he took her to the Gathering on her second day as an apprentice because she had caught a squirrel very well for a new apprentice, and the squirrel had been as big as she was.
The Top Ten. 1 Firestar Firestar is a character in the Warrior Cats series. He's the leader of ThunderClan after Bluestar. He's mates with Sandstorm and has 2 kits: Squirrelflight and Leafpool. He was formerly a kittypet.