A sense of fear is pervading the island. Ever since the littluns started talking about a beast that's supposed to be running loose, the boys have been getting more than a little nervous. There is no beast, of course, but the very idea that there could be one is enough to generate an atmosphere of terror.
At a meeting, Ralph gets straight to the heart of the matter and says that all this stuff about the beast is just littluns' talk. The implication here is that it's babyish to believe that there's a beast running wild on the island. Instead of all this nonsense, Ralph wants the boys to concentrate on important, practical things that will actually give them a sense of purpose.
When Jack takes up the conch to speak, he chews out the littluns, accusing them of starting all this “fear talk”. He acknowledges that everyone gets frightened sometimes, but you just have to put up with it. Those boys who are affected by fear are nothing but “sissies” and “cry-babies”. For good measure, Jack accuses them of not hunting, building, or doing anything to help.
Jack's remarks are somewhat ironic, to say the least. Because in due course he'll expertly manipulate the boys' fear to cement his absolute power over them.