(WITH PLATE V) During March I907, through the courtesy of Dr. J. M. MACFARLANE, I had the opportunity of gathering material for this study from the fine collection of sarracenias in the greenhouses of the University of Pennsylvania. The species examined were S. fiava, S. purpurea, S. variolaris, S. rubra, and S. psittacina, besides the hybrids S. /lava X variolaris and S. flava X purpurea. A close similarity prevails in the pollen of the different species, nor does any marked difference appear in the hybrids. Abnormalities of division among the latter are practically absent. The material consisted of flower buds fixed in chrom-acetic acid. Thin sections of the anthers were stained by the iron-hematoxylin method and with safranin and malachite green. The nucleus of the pollen mother cells contains an intensely staining nucleolus surrounded by a clear space. With safranin and malachite green the color of the nucleolus is red. The surrounding plasm lining ) does not stain deeply, and shows a trace of fibrillar structure (fig. i). The approach of the synapsis stage is indicated by a marked and apparently rather sudden growth in size of the nucleus. The nucleolus also becomes larger, and the clear space surrounding it less well defined but wider. The lining shows more definite indications of a network (fig. 2). A few deeply staining granules now appear within the linin; these increase in number as the network develops (fig. 3). Occasionally granules can be seen in close proximity to the nucleolus (fig. 3), which become larger and irregular in shape, and show a tendency to accumulate in the vicinity of the nucleolus and to surround it (figs. 4-7). In such nuclei there is sometimes evident a similarity in size of pairs of chromatin clumps. Thus in fig. 4 there are visible two masses of chromatin, one on each side of the nucleolus of about the same size; while farther removed from the nucleolus there are two others, smaller than the first, but approximating each other in size. Similar relations are seen in fig. 5. 31] [Botanical Gazette, vol. 45