Architecture and Growth of the Primary Cell Wall in some Plant Hairs and in the Phycomyces Sporangiophore

The cellulose fibrils on the interior surface of the primary cell wall of growing hairs of Ceiba, Asclepias and Gossypium are oriented more or less transversely. In more peripheric layers their direction changes gradually untill they are mainly axial in the outermost layer. Numerous small shallow meshes in the cell wall layers, the shapes, areas and orientation of which vary from the interior to the exterior of the cell wall suggest a new type of cell wall growth, for which the name multi-net-growth is proposed. In Tradescantia staminal hairs and in Phycomyces sporangiophores, an analogous architecture and obviously the same type of growth occur.