In a study of Abies balsamea as a type of the Coniferae, a number of irregularities in the contents of the pollen grain have been observed. Since the material used was collected from different trees and in different years, these irregularities cannot be regarded as abnormalities; and since further examination showed that similar conditions prevail in at least two other species of Abies, these observations have been thought worthy of record. For the material I am indebted to Professor R. WILSON SMITH. A. balsamea was collected in Ontario; A. Veitchii and A. brachyphylla were obtained through the courtesy of the authorities of the Royal Gardens at Kew. The pollen grain of Abies balsamea is very large, its diameter being about twice that of Pinus. At the time of shedding the normal grain contains two prothallial cells, a stalk cell, a body cell, and a tube nucleus, imbedded in a vacuolated protoplasmic mass which contains numerous starch grains (fig. I). The nucleus of the body cell is surrounded by dense protoplasm and a cell membrane. The tube nucleus is large and usually compressed; in some instances the pressure, resulting from the extraordinary growth of thcells of the gametophyte, is insufficient to force it from its polar position to a lateral one. The stalk cell is much smaller than the body cell, and quite frequently is compressed into a cavity at the prothallial end of the latter. In A. Veitchii and A. brachyphylla the prothallial cells are very much flattened at this stage; but in A. balsamea it is not uncommon to find both prothallial cells retaining the characteristic nuclear structure. The size and permanence, however, varies with the individual as well as with the species. The material examined does not show stages earlier than the division of the central cell into generative cell and tube nucleus. Peculiarities in this division are described later. The periclinal Botanical Gazette, vol. 57] 1I48