The Value of Certain Nutritive Elements to the 
Plant Cell . 1 
BY 
HOWARD SPRAGUE REED. 
With two Figures in the Text. 
I. Introduction. 
I T is my purpose to describe in the following paper the results of a study 
upon the role of certain essential elements in the physiology of the 
plant cell. Since the times of De Saussure and Boussingault it has been 
known that the complete development of the higher plants and of many of 
the lower ones requires soluble salts of ten different elements, each one of 
which possesses a relatively low atomic weight. Some of these elements, 
like iron and magnesium, are required only in small quantities, but a certain 
amount is indispensable to practically all plants. 
The studies of such investigators as Wolf, von Raumer, Loew, and 
others, have shown that certain of these essential elements accomplish more 
or less definite functions in the growth and fructification of the plant. 
There is every reason to believe that the different essential elements also 
perform more or less definite functions in the physiology of the cell. 
However, we have much less scientific evidence upon the latter subject than 
upon the former. Molisch (’95), Bokorny (’95), and Loew (’92, ’99), have 
furnished some valuable data upon this question. 
The majority of the workers who have studied the role of the essential 
elements in plant metabolism have worked upon the assumption that the 
almost exclusive function of these elements is to furnish chemical com- 
pounds suitable for elaboration into plastic and aplastic materials and fluids 
of the plant. As a result of my experiments I feel justified in advancing the 
opinion that the inorganic food constituents of the plant may also indirectly 
perform functions of the greatest value to the plant without necessarily 
entering into the composition of any of its parts. 
The plant cell is an especially favourable object for studying the role of 
the essential elements, because it takes its food in the form of comparatively 
1 Contribution 15 from the botanical laboratory of the University of Missouri. A thesis presented 
to the Graduate Conference, 1907. 
[Annals of Botany, Vol. XXI. No. LXXXIV. October, 1907.] 
