The hypochromic effect in DNA is discussed using a non-retarded version of earlier work of the author based on the response function. Single particle or incoherent excitation is distinguished from coherent Frenkel excition response and a model is presented in which different transition dipoles are coupled differently to their neighbours. This is justified by the extreme degree of asymmetry present in the DNA polymer so that dipole lattice sums depend on the relative orientations of the dipole and the polymer rod axis. It is found that the obsorved hypochromic effect without shift in frequency of the lowest frequency absolution maximum can only be accounted for if the lowest transition dipole yields a small value for the dipole lattice sum.