Dr. Page, I must congratulate you for being able to put some order into all these scattered data on fibre strength. However, I think you have made your analysis too simple by totally neglecting any contribution from the hemicelluloses. If we make an exhaustive model calculation starting from the molecular properties and including all the different fibre wall layers, we may estimate the contribution from the hemicelluloses. In your paper, you have used relations for the modulus \ of the fibre as an indication of its strength. For comparative purposes, I have adopted the same simplified approach, since the calculations are more straight forward. The model I am using has been presented elsewhere (1,2) and involves the fibre wall layers S₁, S₂, and S₃. It has been shown to give a good estimate of the modulus of fibres (1,2).