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.
Tybalt is the cousin to Juliet. He is referred to as the Prince of Cats as he is a skillful fencer and kills all the mice he encounters. Tybalt is unwilling to tolerate Romeo's presence at the Capulet party and seeks revenge. When he finally meets Romeo in the street, Romeo refuses to fight.