Summary: The reactions of recoiling carbon atoms produced via the 14N (p, α) 11C process have been studied in gaseous and liquid methylamine, with and without scavenger. The product forming mechanisms in this system seem to follow the general pattern of the chemistry of energetic carbon atoms in simple hydrocarbons. The major products resulting from fragmentation of excited intermediates are acetylene and ethylene. As expected ethylamine and dimethylamine are found as the synthesis products. A small yield of acetonitrile, which remains unaffected by the presence of scavenger or the change of phase, is also found. In agreement with the deexcitation-fragmentation hypothesis the yield of the fragmentation products acetylene and ethylene decreases while the yield of the synthesis products ethylamine and dimethylamine increases in the condensed phases. The formation of the products is explained on the basis of insertion reactions. From comparison of the acetylene and ethylene yields in methylamine with those in the ethane system it seems that C-Η bonds are much more reactive towards insertion reactions than N-H bonds. Whether this is due to a lower reaction probability or to a more easily stabilized intermediate cannot be decided on the basis of the present evidence. Furthermore, the comparison with alkane systems shows no effect of the "leaving group" on the postulated acetylene and ethylene producing fragmentation process. It is suggested that the formation of acetonitrile takes place via decomposition of an excited ethyleneimine molecule, since the activity is equally distributed between the two carbon atoms.