480 Fixation of Free Nitrogen by the Lower Green Plants. 
could grow (Mosses and Algae possess no roots). In tliis series of 
experiments there was no fixation of free nitrogen, neither by the 
soil nor by the plants other than peas. 
The investigators arrive at the following conclusions : — 
1. The Leguminosae (division Papilionaceae), as represented by 
peas, are able to draw largely upon the free nitrogen of the air for 
purposes of growth. 
2. Some of the inferior green plants possess the same property. 
3. In the conditions under which the experiments were con- 
ducted, bare soils — that is, soils devoid of any apparent vegetation 
— failed to fix free nitrogen in any measurable quantity. Oats, 
mustard, cress, spurrey likewise failed to fix the free nitrogen under 
conditions identical with those in which peas fixed it abundantly. 
Of the preceding conclusions it is the second one which will 
especially force itself upon the attention of those who have followed, 
during recent years, the course of discovery in this important field of 
investigation. The authors admit that Frank had already (1888 
and 1889) claimed for some of the lower green plants the property 
of fixing free nitrogen. They argue, however, that his proofs were 
indirect and insufficient. They further note that MM. Arm. 
Gautier and R. Drouin had encountered these humble green plants 
in the course of experiments upon the fixation of nitrogen, but had 
regarded them as instrumental in promoting the absorption only of 
combined nitrogen, and had rejected the idea of a fixation of free 
nitrogen by their means. 
It deserves to be recalled that under the terra “ inferior green 
plants ” the authors designate a complex assemblage of lowly 
organised plants, amongst which were recognised certain Algae and 
certain Mosses, some of the latter attaining an inch in height. It 
was to this assemblage of plants that the fixation of free nitrogen 
was attributed. 
If we accept the results of the elaborate research of MM. 
Schlcesing fils and Laurent, it becomes necessary to extend the list 
of nitrogen-fixing plants so as to include, not only papilionaceous 
plants, but some at least of the Mosses and Algpe. It is a fact 
known to all who are familiar with meadows and pastures that these 
are liable at certain seasons of the year to be invaded by mosses and 
other cryptogams, some of which, we learn, are capable of fixing the 
free nitrogen of the atmosphere. When, with tlie advance of spring, 
these humble plants die, they must enrich the soil with the nitrogen 
that they have acquired. 
When a soil commences to form upon what has hitherto been 
bare rock it is the same lowly plants which first take possession of 
the surface. Is it not possible that the stores of nitrogen which our 
cultivated soils contain were begun long ago by mosses and other 
rootless plants, which represent the highest forms of vegetation the 
incipient soil is capable of supporting % 
Whether Mosses and Algae possess the power of direct assimila- 
