The image is a detailed, black and white botanical illustration of a cross-section of a stem, specifically identified as 'Mare's Tail' (Hippuris vulgaris). The stem is circular in shape and appears to be a magnified view, indicated by the 'x 14' notation. The interior of the stem is filled with a honeycomb-like pattern of numerous small, polygonal cells. These cells are arranged in a radial pattern, emanating from a central, darker core. The cells are not uniform in size or shape, but generally appear rounded or slightly elongated. Within each cell, there's a fine, dotted texture, suggesting internal structure. The cells are separated by thin, dark lines, creating a clear delineation between them. The outer edge of the stem section is slightly irregular, giving it a natural, organic appearance. Below the illustration, there's text identifying the figure as 'Fig. 44. STEM OF SECTION OF MARE'S TAIL (HIPPURIS VULGARIS)' and a note '[to face page 145.'.