May, 1923] 
REED — SPECIES CONCEPT 
237 
from an organism it cannot be engendered, as much bacteriological experi¬ 
mentation has demonstrated. 
It may be concluded, therefore, that, as a cell digests or does not digest 
the substances with which it becomes associated, it synthesizes the sub¬ 
stances for which it has hydrolytic or dehydrolytic enzyms. 
R. S. Lillie has recently brought forward a theoretical explanation of 
this synthetic action which, if it can be supported, is most attractive. 
The cell proteins he considers exert a type of autosynthetic action, pre¬ 
sumably by the dehydrolytic condensation of amino-acids. The energy 
transformation in certain of these reactions he considers to be too great to 
be accounted for by enzym action, and he finds the formation of electrical 
circuits between different regions of the cell to account better for the 
observed reactions. 
Considerations of such phenomena as emphasized by Rettger’s work on 
the growth of various species of bacteria in the same mixture of amino-acids 
and other simpler nitrogen compounds may serve to visualize specific 
synthesis. From such a mixture the various species grow and multiply in 
their characteristic form, which necessitates that they synthesize their 
characteristic body proteins, and these we know from serology to be chem¬ 
ically distinct. 
IV 
If species are characterized by the presence of specific chemical sub¬ 
stances, species continuity as well as individual development must depend 
upon the constancy of the specific synthetic reactions. Any deviation 
from the characteristic reaction in a cell resulting in atypical end products 
will of necessity alter the chemical specificity; which alteration may be 
exhibited in atypical activity, pleomorphic form, or death. 
Some recent data concerning the origin and nature of pleomorphic 
bacteria may be interpreted as resulting from modified synthetic activity. 
We found that the form of the influenza bacillus could be greatly altered 
by the H-ion concentration of the culture medium. In a medium of suffi¬ 
cient acidity or alkalinity to be near the growth-limiting reaction, a large 
percentage of the organisms appear in very distinct pleomorphic form, 
frequently a hundred times larger than the typical. Moreover, these 
atypical forms entirely resist the agglutinating action of specific serum and 
therefore lack the antigenic proteins of the normal cells, a deficiency evi¬ 
dently resulting from altered synthesis imposed by the reaction of the 
environment. Such an effect might be expected from the familiar action 
of H-ion concentration upon the proteolytic enzyms. 
The transmission of chemical specificity through a specialized germ 
plasm has received no attention from the present point of view. Yet we 
might interpret Guyer’s recent familiar results concerning the inheritance 
of experimentally induced eye defects as a case in point. Guyer prepared 
an anticrystalline-lens serum by immunizing fowls with macerated rabbit 
