What Does the Spiral in a Sestina Mean?

[ƒ(x)]

So, I have to write a sestina for english class. While searching wikipedia, i came across this image

I suspect this has something to do with being tired, but what does the spiral mean? I'm with it as far as the first transition (going clockwise). The sixth line does indeed become the first. But, after that it becomes the 2nd, not the 5th...

Am I missing something obvious?

 

[Containment]

Is it like a traveling salesman thing or something?

Where did you find it?

Oh it's poetry... that explains the total lack of logic to it.

 

[Newai]

It's here: http://en.wikipedia.org/wiki/Sestina

 

[renz]

Read the spiral clockwise. Follow roman numeral for each set of 6 numbers (read each column). So the first set (I) is just {123456}. The second set (II) is {615243}; that comes from following the spiral clockwise. The first knot is at I-6, then I-1, then I-5, and so on.
For the third set (III) you do the same thing but read number from column II.

 

[ƒ(x)]

Alright, thanks.