No. 466.] STUDIES ON PLANT CELL. VIII. 705 



nuclei in higher plants. The earlier investigators for the most 

 part failed to recognize the chromatic granules and network 

 and considered the nucleolar body (nucleolus) to be ^the- nucleus 

 of the cell. Janssens and Leblanc ('98), however, described a 

 nucleus with a membrane containing caryoplasm and a nucleolus, 

 and other authors noted the vacuole and believed that it held 

 some relation to the nucleus. 



Both the nuclear vacuole and the nuclear body (nucleolus) 

 take part in the process of bud formation. The bud appears on 

 the opposite side of the cell from the nuclear body and the nu- 

 clear vacuole lies between. The bud contains at first cytoplasm 

 alone ; then the nuclear vacuole begins to pass into it and the 

 nuclear body takes a position in the vicinity, between the 

 mother-cell and the bud. The nuclear body now divides by 

 simple fission and one half enters the bud. The nuclear vacu- 

 ole gradually constricts and is drawn apart in the canal between 

 the two cells. The two daughter nuclear vacuoles and nuclear 

 bodies then pass to opposite ends of the mother- and daughter- 

 cells respectively. If the nuclear vacuole is absent the chroma- 

 tin network is drawn apart so that a division is effected in a 

 similar manner. 



At the time of spore formation, the chromatin is reported by 

 Wager to become so closely associated with the nuclear body 

 that the two substances cannot be easily separated and behave 

 as one. The resultant structure elongates and divides by con- 

 striction and the subsequent divisions are of the same character. 

 Strands of deeply staining protoplasm between the daughter 

 nuclei are of interest as suggesting the possibility of a simple 

 type of spindle. Wager describes the formation of spore walls 

 around the nuclei enclosing a portion of the protoplasm and 

 thus cutting the spores out from the remaining non-nucleate cell 

 contents. The details of this process are not known and might 

 prove very interesting since the process, from W'ager's account, 

 would seem to be one of free cell formation without, however, 

 the characteristics described by Harper in spore formation 

 within the ascus. It should be more thoroughly studied for it 

 is possible that the division will be found to involve cleavage 

 furrows and really prove to be a type of segmentation by con- 

 striction (Section II, Amer. Nat., vol. 38, p. 453, June, 1904). 



