A variety of examples are given from different areas of biology to illustrate the general applicability of matrix algebra to discrete models. These models of biological systems are concerned with relations between processes occurring in discrete time intervals. Diffusion, ecosystems, and different types of cells are modeled. (KR/Author)

Two properties of a wing, namely aspect ratio and wing loading, are described and the matrix approach is used to make certain deductions about particular wing plans. Some examples are provided which show how the matrix transformation of one wing plan into another brings about predictable changes in wing properties. (KR)