Observations on the Action of X-rays on 
Plant Cells. 
BY 
MAUD WILLIAMS. 
Introduction. 
T HE present work arose out of experiments upon the changes produced 
when certain plant cells are immersed for long periods in solutions of 
electrolytes (1). An empirical formula had been obtained connecting the 
concentration of a particular salt solution employed and the time of immer¬ 
sion needed to produce a specific change in the cells studied. This change, 
which is also employed in the present work, was judged to have taken place 
when a o*i per cent. K 2 Cr 2 0 7 solution was able to enter the cells and com¬ 
bine with the tannin contents to yield a precipitate within a time limit of 
three minutes. The results obtained for series of salts made it seem de¬ 
sirable to study the influence upon living protoplasm of electric charges of 
one kind only, unhampered by the presence of undissociated molecules or 
of salt ions. 
Treatment with radium seemed a possible way of attaining this object. 
The ordinary radium bromide preparations give off a particles (positively 
charged), /3 particles (negatively charged), and X-rays of a very hard type. 
By using the preparation encased in mica or platinum the a particles are 
absorbed and the cells can be submitted to the bombardment by the nega¬ 
tively-charged particles, which travel with great velocities, and to the action 
of the X-rays. It is obvious that the influence of the (3 particles alone can 
be estimated only when the effects of the X-rays themselves are known. 
Although it is not suggested that treatment of plant tissues by either 
X-rays or by radium is likely to be of practical importance, the investiga¬ 
tion of cell behaviour when under these radiations is of great interest from 
the following points of view: 
(a) Possible stimulation. 
(b) The coagulation of colloidal matter. 
(c) The action of etheric radiations of very short wave-length upon the 
colouring matters of cells. 
The second of these matters is that of chief interest in the work under¬ 
taken, but various interesting changes have been observed, and it is pro¬ 
posed to deal with the experiments in a series of short papers. 
[Annals of Botany, Vol. XXXVII. No. CXLVI. April, 1923.] 
