This paper presents results of cytological observations on microsporogenesis of the semperflorens and caturra varieties of the species Coffea arabica L. In general meiosis was found to be normal, the gametes having n = 22 chromosomes. Only minor irregularities were observed and these were limited to distribution of the chromosomes. In the early prophase of meiosis the chromosomes did not stain well. In the pachytene stage the chromosomes stained comparatively well and showed several hetero-piknotic regions separated by very fine sections which stained faintly. The centromere was readily seen and was located between two heteropiknotic sections. The extremities of the arms of the chromosomes stained very poorly and were lost to view in the cytoplasm. The nucleolus was easily visible and some of the chromosomes appeared to be attached to it. The exact number of chromosomes that were attached to the nucleolus appear to vary from one to four. From the pachytene stage the chromosomes passed very rapidly to metaphase I. In the diplotene stage the chromosomes were observed to be very short and the centromeres could not be seen. In the diakinesis stage the darkest colored parts of the 22 pairs of chromosomes, especially where the centromeres were located, were well separated indicating that they repelled each other. In contrast the slightly stained regions of the chromosomes were intimately associated and showed chiasmata. The number of chiasmata per cell varied from 29 to 43, the average per bivalents being 1.67 in semperflorens and 1.75 in caturra. In metaphase I the average number of chiasmata per bivalent was determinated as 1.69, in semperflorens and 1.67 in caturra. In anaphase I the 22 pairs of chromosomes were normally separated and in telophase I the chromosomes did not stain well, again making detailed observations difficult. Practically no interkinesis was observed. Following telophase I the chromosomes were observed to contract and entered into anaphase II, that was observed to be normal. The formation of microspores appeared to be normal. After separation of the microspores there occured a division of the nucleus giving origin to two nuclei with 22 chromosomes each. This was observed ot occur three to four days before opening of the flowers. The vegetative nucleus was observed to be large, round, homogeneous, and stain only faintly. The reproductive nucleus was observed to be small, reticulated ; it stained well, and was located at the periphery of the cell. The reproductive nucleus was usually found to be surrounded by a small amount of cytoplasm in a lenticular shape. The division of the reproductive nucleus usually takes place in the pollen tube. Both vegetative and reproductive nuclei were observed to occur in the extremity of pollen tube.