Logging received messages to stream:out

[Simple Appointment]

I am new to camel and would like to use it as our integration component. 
I was trying to log messages received from a jms queue to the console 
and it seems that the messages accumulates. Lets say I have messages
one,two,three,four in my queue.

    def configure(): Unit =  {
      from("activemq:TEST.FOO")
      .log(" stream:out")
    }

What I get is:

one,
one,two
one,two,three
one,two,three,four

I was expecting
one
two
three
four

Am I missing something?