Further observations on cell-wall structure as seen in cotton hairs

The present note summarises the results of observations made subsequently to the recognition of growth rings in the cell-wall, of which a photograph in transverse section is given in Plate 10, fig. 2. These observations are all related to previous physiological studies, and most of them have been made on material of known origin, i. e., dated bolls and pure-line plot crops. An excellent memoir on our present knowledge of the cotton cell-wall by Mr. H. J. Denham, now in course of publication, makes it unnecessary for us to deal with the historical aspects of the matter.