The Effect of Gases on Nuclear Division. 
BY 
FRANK M. ANDREWS, 
Assistant Professor of Botany in Indiana University , Bloomington , Ind. y U.S.A* 
With a Figure in the Text. 
E VER since the appearance of Demoor’s paper 1 on the physiology of 
the cell, considerable doubt has been expressed as to the exactness 
of many of his experiments and conclusions 2 . It was in the hope of 
removing this doubt that I began an investigation at the suggestion 
of Prof. Pfeffer, during my study in Leipzig in 1902, to ascertain the 
correctness of Demoor’s work. My experiments, to be described presently, 
do not include the whole of the work mentioned in the paper of Demoor 
cited below, but deal only with Chapter IV (pp. 30-54). This chapter 
contains the results of his experiments on the staminal hairs of Tradescantia 
virginica , especially under the influence of different gases, with reference to 
protoplasmic and nuclear activity. It is, however, his statement that the 
nucleus can be divided independently of the protoplasm that is most 
important and has caused most controversy, and it is this question that 
I have tried especially to decide by my experiments. 
Methods. 
Momordica E later inm was used only for a few experiments on the 
movements of protoplasm. The best as well as the most certain living 
object, however, in which nuclear and cell-division can be directly followed 
is Tradescantia virginica 3 , and accordingly this plant was chosen for my 
investigations. The younger staminal hairs, and those containing cells 
whose nuclei had not yet divided, were selected and put in a 3 per cent, 
solution of cane sugar to see the division take place. This solution 
is not concentrated enough to produce plasmolyzation, nor does it 
apparently interfere in any way with the vital activities of the cell — at 
1 Contribution a l’etude de la physiologie de la cellule. Archives de Biologie, tome xiii, 1894. 
2 Pfeffer, P fl anzenphy siologie, 2. Aufl., Bd. ii, p. 46. Samassa, Ueber d. Einwirkung von 
Gasen auf d. Plasm astromung, Bot. Zeitung, 1898. 
8 Strasburger, Botanisches Practicum, 4. Aufl., 1902, p. 589. 
[Annals of Botany, Vol. XIX. No. LXXVI. October, 1905.] 
