States of ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$ have been observed whose excitation energies appear to be correlated with thresholds for neutron emission to excited states of ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$. It is pointed out that similar correlations occur in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, and the correlation is discussed in terms of known threshold effects.

• Received 20 October 1969

DOI:https://doi.org/10.1103/PhysRevC.1.1710