February, 1934 The Queensland Naturalist 
11 
basis for at least two of the most fundamental processes 
functioning in a primitive organism. 
1. It is a highly suitable source of energy. 
2. It is a powerful medium for attracting the 
carbon dioxide of the air which supplies the 
carbon for the structural framework of the 
essential constituents of living substance. 
The principal processes functioning in the living 
activities of the iron bacteria Spirophyllum and Lepto- 
thrix are essentially similar to those operating in the 
protein-producing experiments. 
(1) The general conditions in the highly charac- 
teristic experiments carried out by Lieske in 
the cultivation of Spirophyllum and those 
now carried out with the production of 
protein are similar. A solution of the same 
chemical composition was used in each in- 
stance. 
(2) The most essential condition for the growth of 
Spirophyllum and Leptothrix is reduced to 
the same basis as the primary reaction in the 
production of protein in the experiments : a 
combination of carbon dioxide with iron in 
the ferrous state. 
(3) The nitrogen relationships in Lieske ’s experi- 
ments with the growth of Spirophyllum and 
those with the production of protein are evi- 
dently very similar. When either of the two 
nitrogen-containing compounds in Lieske ’s 
solution was omitted in the experiments the 
amount of protein produced was greatly 
diminished. 
(4) The process providing the energy for the 
functions of Spirophyllum and Leptothrix is 
strictly similar to that in the protein-produc- 
ing experiments. In each instance the energy 
is provided by the oxidation of a ferrous com- 
pound to ferric hydroxide. 
From the remarkable similarities, both general and 
special, which are shown in each instance, it is concluded 
that the processes involved in the nutrition and respira- 
tion of Spirophyllum and Leptothrix are essentially 
similar to the processes functioning in the protein-pro- 
ducing experiments. 
Granules of the nucleo-protein chromatin are located 
in the cells of the iron bacterium Leptothrix ochracea 
