We note in passing that for the majority of the gene sequences of the vertebrates, the 2D plots display an overall shape that is concave going in the clockwise direction; correspondingly, the coefficient of the second degree variable is negative. This is seen even in the case of the chicken beta globin gene where the large intron component makes it GC-rich, the human beta globin gene which is AT-rich, as also the alpha globin genes of the horse, rhesus monkey and human which are all GC-rich. Plots of some viral sequences such as the H5N1 neuraminidase, on the other hand, have concavity in the opposite direction and the sign of the coefficient of the second degree variable is positive. Interestingly this is also seen in the case of the wheat histone H4 gene, which is claimed by some authors to have viral features [35] ; their origins from before the eukaryote split could also be a factor. Whether this is just chance coincidence or whether it is symptomatic of some deeper characteristic arising from base composition and distribution differences in prokaryotic and eukaryotic sequences remains an intriguing question.