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.
Return to the dawn of the Clans to discover how the warrior cat Clans came to be. A cryptic prophecy from StarClan draws three young cats together and threatens the fragile balance between the four warrior Clans. Download Warriors to your tablet or ereader with original Warriors eBooks by Erin Hunter.