96 



groups were separated front each other by a layer of tissue from one to 

 three cells in thickness. The central cells of two of the archegonia of 

 the end group had fused at the outer ends only, although the sheath cells 

 had entirely disappeared along the contiguous sides, leaving only a deli- 

 cate line between the plasma membranes of the slightly shrunken cells. 

 No nuclear fusions had taken place. Near each of these several arche- 

 gonia one or more sheath cells had begun to bud out apparently to form 

 archegonia as figured by Miss Ferguson (I.e., Fig. 265). In several 

 preparations showing one or more of the anomalies herein mentioned, the 

 enlargement of one or more of the sheath cells was of frequent occurrence. 

 These enlarging cells possessed each a large nucleus and a dense cytoplasm, 

 showing that they were being well nourished. In one ovule presenting 

 a group of archegonia at each end of the endosperm, two large cells very 

 poor in cytoplasm and about one-third the size of the normal archegonia 

 lay between a normal archegonium and the end of the gametophyte at the 

 chalazal extremity. From all appearances they had developed from 

 sheath cells. They were not surrounded by jacket cells, hence their sparse 

 cytoplasm. 



Of this class of anomaly, namely, the presence of archegonia at oppo- 

 site ends of the gametophyte, a few cases were observed in which there 

 were three separate groups, one at each end and one at one side nearly 

 midway between the extremities. In another instance the nucleus of the 

 central cells had divided, the two daughter nuclei, which were well formed, 

 lying in contact side by side. In this ovule all archegonia were immature; 

 the ventral canal cells were not formed, and there was no fusion of the 

 central cells. The two nuclei must, therefore, have been formed by the 

 division of the nucleus of the central cell. 



A second class of anomaly was observed in a single instance. It was 

 the presence of a pollen tube containing supernumerary nuclei. This tube 

 had grown down prematurely along one side of the endosperm and had 

 just begun to indent the latter. The tube contained the two male nuclei 

 surrounded by the cytoplasm of the body cell, together with about twelve 

 other nuclei varying greatly in size. The largest of these nuclei were 

 about the size of the male nuclei or larger. Their structural details 

 were sharp and distinct ; each contained a very distinct, but delicate, 

 nuclear net with two or more relatively small nucleoli. In the same ovule 

 another pollen tube had traversed about two-fifths of its way down through 

 the nucellar tissue. In this ovule archegonia were present at each end 



