Left: comparing the CO fundamental line profile from HH 100 as seen in observations separated by 11 months. The profiles shown here are the co-added lines of P(4), P(6), P(7), and P(8). No significant difference is seen in the emission line profile between the two epocsh. In August 2008 the wind absorption at −75 km s^-1 was deeper than that seen in September 2007. Right: co-added CO emission from two observations of WL 12. The observation of September 2007 covered low-J lines while the observation of March 2010 covered high-J lines, so the comparison of line profiles is not direct. Some of the wind absorption in 2007 appears to go into emission in 2010.