MORPHOLOGY AND DEVELOPMENT OF EUDENDRIUM. 43 



egg wall becomes defined again it includes the contents of other 

 cells. Allen, 'oo, working on Tnbularia crocea was led to 

 Doflein's view, though the fact that the absorbed cell sometimes 

 retains its outline in the egg is suggestive of amoeboid activity-. 



The egg of E. Jiargitti is largely passive in the process of cell 

 absorption. A syncytium-like structure is formed by the disap- 

 pearance of the egg membrane in a limited region, and of the 

 walls of adjoining entoderm cells. The border of the egg is, 

 later, again defined, not by its activity so much as by the growth 

 of the spadix which removes the egg from its former position. 

 It is not surprising that the behavior of the egg finds an approxi- 

 mate parallel in T. larynx and T. crocea, when we consider that 

 these species belong to a closely associated genus. 



There has been a diversity of view as to the fate of the nuclei 

 of cells absorbed by hydroid eggs as well as to the method of 

 absorption. Ciamician, '79, applied the term " pseudozellen " to 

 spherical bodies found in the egg of T. mesembryanthemum which 

 he considered to be formed after the nuclei of the absorbed cells 

 had disappeared. Brauer, '91, published the results of the study 

 of the same species, in which he agreed with the conclusion of 

 Ciamician as to the origin of the pseudo-cells. Also, in a con- 

 tribution to the development of Hydra, he says that pseudo-cells 

 are formed in the cytoplasm and are not degenerating nuclei. 



The three papers already mentioned, by Doflein, Smallwood 

 and Allen, described the nuclei of absorbed cells as undergoing 

 divisions and degenerative changes characteristic of pseudo-cells. 

 That name is therefore applied to them. 



In this species, the history of the nuclei does not exactly cor- 

 respond to any that have been outlined above but finds its closest 

 parallel in the persisting of nuclei as pseudo-cells. I hax'e not 

 as much evidence as I would like regarding the absorption of 

 nuclei by the egg near the place of its origin. This is due to the 

 difficulty encountered ill finding very young eggs. A consider- 

 able part of those I did find had nuclei of ectoderm cells, thus 

 rendering it probable that there is an early stage of the egg when 

 growth is expedited by the absorption of a few cells. For two 

 reasons, I am convinced that the nuclei are absorbed before the 

 egg leaves the pedicel ; first, no extra nuclei were found in many 



