Jan. 17, 1916 
Plenodomus fuscomaculans 
717 
3. Growth and reproduction differ also in that the working limits of the general 
life conditions, temperature, oxygen, etc., are narrower for reproduction than for 
growth. On this account growth can still take place, even if reproduction be limited 
through too weak or too strong influence of some factor. 
4. Growth appears mostly as a preliminary for the initiation of reproduction, and, 
therefore, as an inner condition for it. Up to a certain limit, not directly growth, but 
the longer assimilation period is determinative. 
From this point of view all the factors which influence life may be 
considered, and from the basis of the knowledge of their effects on 
growth, the ultimate effects of these factors upon reproduction may be 
predicted more or less accurately. This Klebs (1900, 1904) has done 
in the summary of his contributions to the physiology of reproduction. 
Since that time research along this line may be divided into two types 
of endeavor: (1) Extending the groups to which the laws may be shown 
to apply and (2) the critical testing of the conclusions with the very 
organisms with which Klebs worked. The former has extended the 
limits so that none of the great groups of fungi or algae are without 
many examples of the application of the conclusions. The work of the 
second type has opened up new points of view. Klebs in his experi¬ 
ments used a single strain, and the common experience, in repeating his 
experiments, is failure until the limits and life relations of the particular 
strain at hand are known. Accordingly, Kauffman (1908) has empha¬ 
sized this point in his work with the same species of Saprolegnia that 
Klebs used; but where Klebs worked with one strain, Kauffman used 
two additional ones; and with this number of forms, each an entity and 
each varying from the other, Kauffman was able to show that within the 
limits of each the conclusions were valid. This work emphasizes a 
point which Klebs has made for his various forms, that each is a specific 
potentiality, but it makes the specific potentialities innumerable in 
their scope. 
‘ The particular organism with which I worked was one closely related 
to the large genus Phoma. This group, although containing many 
species, some of great economic importance, had received little attention 
from a physiological point of view. There have been no attempts to 
test the validity of Klebs’s conclusions for the Sphaeropsidales. 
Ternetz (1907) isolated from the roots of species of Vaccinium and 
Oxycoccus a series of Phoma spp. suspected of being mycorrhiza-pro- 
ducing forms. These organisms were grown in pure culture on synthetic t 
media, and their relations to oxygen, nitrogen, and mineral salts were 
determined with great care. They were found to be sensitive to a restric¬ 
tion of the oxygen supply, especially when growing in a medium poor in 
nitrogen. These organisms were shown to have the power of utilizing 
nitrogen from the air. Saida (1902) has claimed the same for Phoma 
betae. 
Eater, Konig, Kuhlman, and Thienemann (1911) cultured a species of 
Phoma isolated from water, and although they secured pycnidia in a few 
