Through the use of Stromgren uvby photometry we show that most likely all g
lobular cluster giants posess large (factor 10) variations in their abundan
ce of nitrogen, as revealed by large star-to-star variations in their cl in
dex. We find that these variations are present in faint RGB stars which sho
uld not have experienced mixing - this points to the possibility that the m
ain source of these variations are due to early generations of massive shor
tlived stars polluting the cluster enviroment during the formation process.