Intermittent strands - bad Makerbot yellow filament - correction

Correction, in retrospect, the filament wasn't bad, it was the plunger in my extruder.

A lot of my larger prints are quitting about halfway through.
On this print, you can see the intermittend strants in the lower layer.
I switched to my SainSmart white filament and the problem went away.

Conclusion: my Makerbot yellow filament, which can print fine for about an hour, is buggy, an therefore a waste of time and money.