Trouble in R with abline : it's my first time using R - I've only used SPSS before and this is all very confusing for me.

I'm having trouble plotting 2 ablines on a graph of the log10 Brain mass and log10 body mass. I'm following someone else's script but it just doesn't work for me. This is what I have: [Click me][1]
(I've taken a screenshot of it because when I write it out here it comes out all weird ;_;)

This is the graph produced:
[Click me!][2]

Why are the lines off there like that? Are the values I'm getting for the intercept and slope incorrect, or am I using the wrong ones? I've done other examples of this and its worked ok, but I've always ended up using the first model, never the second one so I'm not sure if I'm using the right values.

Thank you :)


  [1]: http://i.stack.imgur.com/pjWTl.png
  [2]: http://i.stack.imgur.com/I0Cla.png