1903] MITOSIS IN PELLIA 31 
and fro in the alcohol. Clove oil was used for clearing. The 
clove oil should be rinsed off with good cedar oil, otherwise the 
gentian violet gradually fades. When orange G was used the 
preparations were taken from the gentian violet, dipped a few 
times in water, stained for one minute in orange, and then trans- 
ferred to the absolute alcohol. 
In studying the preparations glass globes, filled with various 
solutions, served as ray filters and condensers. A light blue 
solution of ammoniated copper sulfate was used for most of 
the work, but occasionally a light violet solution of permanganate 
of potash, imitating the gentian violet stain, gave a sharper dif- 
ferentiation of the kinoplasmic structures. 
While the work deals chiefly with the first three divisions of 
the germinating spore of Pellia epiphylla, and in these divisions 
is largely confined to the centrospheres, asters, and spindle, 
mitosis was studied in other phases of the life-history of this 
genus, and also in several other liverworts, among which were 
Conocephalus, Marchantia, Aneura, Pallavicinia, Scapania, Lopho- 
colea, and Porella. 
The principal results of the investigation were presented ina 
Vortrag before Professor Strasburger and the advanced students 
of the Bonn laboratory in February 1902, and in July of the 
Same year a brief résumé was presented before the botanical 
section of the American Association for the advancement of 
cience, 
THE SPORE MOTHER-CELL. 
The spore mother-cell was observed in Pellia epiphylla, P. 
¢alycina, Aneura multifida, and in Porella platyphylla. In all of these 
forms the nucleus occupies a central position during the develop- 
ment of the lobes which are to become spores. It seems probable 
that the nucleus is concerned in the formation of the lobes. We 
found nothing to support Davis’s (7) statement that the nucleus 
lies in one of the lobes until shortly before the first division of the 
mother-cell. No quadripolar spindles, like that described by Far- 
Mer (7) for Pallavicinia, were found in any of the above-mentioned 
forms. On the contrary, the four spores in all these cases are 
formed by two successive divisions, as described by Farmer (10) 
