VEGETATIVE CELL DIVISION IN ALLIUM. 
MABEL L. MERRIMAN. 
(WITH PLATES XI~-xII1) 
Brrore the controversies which have arisen over the occur- 
rence of reduction in plants can be settled or the problems as to 
the nature of fertilization can be attacked, a detailed study of 
dividing and quiescent plant cells is made necessary. The vege- 
tative or typical division of plant cells from which the factors 
of sexuality and reduction are eliminated must be understood 
before deductions can be made as to the significance of the mode 
of origin and distribution of the chromosomes occurring in 
atypical divisions. 
| Accordingly, this research was undertaken with the hope of 
adding to our knowledge of the processes of vegetative cell 
division, and also of paving the way for further investigation of 
these processes as affected by variation of external conditions. 
The material used is Allium root tips, already known as excep- 
tionally favorable for the study of karyokinesis. It was also 
considered an advantage, in order to secure a more thorough 
survey of the subject, to employ material which had furnished 
the text of other publications. 
TECHNIQUE. 
The following solutions were used for the fixation of the cells : 
chrom-acetic-osmic, both the weaker and stronger solutions as 
employed by Flemming, chrom-acetic acid (chromic acid 0.9 
per cent. and acetic acid 0.1 per cent.) ; the solution recommended 
by Carnoy as composed of one part glacial acetic to six part 
absolute alcohol and three of chloroform; and finally a solution 
made up of saturated picric acid one part, sublimate one part, 
to two parts of water. Cedar oil and xylol were used as clear- 
ing fluids. The best differentiation of the chromatic substance 
was obtained with Heidenhain’s iron alum haematoxylin in co 
bination with some cytoplasmic stain. The triple stain, safranin 
l 
178 MARCH 
