Oct. 1 , 1926 
Telial Sorus in the Pine Rust 
649 
structure into four cells are not laid down. There are two nuclei in 
each of the cells of the two-celled promycelium, and two nuclei are 
supposed to enter each sporidium. Lindfors shows two teleutospores 
germinating with long germ tubes, and he states that Grove had 
found four-celled promycelia in this species. Evidently this species 
of rust must receive further attention before it can be compared with 
the strain of the short-cycled Caeoma nitens which develops two- 
celled promycelia. 
In any system of classification based on morphology it may be 
asked just how important, as showing relationship, is the manner of 
germination of a spore. Grove (11) says, “It is, indeed, doubtful 
whether the character upon which the Coleosporiacae are united into 
one group, viz, the internal basidium, is really an indication of 
close affinity/ 7 
If the spores of Chrysomyxa abietis , which according to Kursanov 
(12) and Lindfors (13) are borne in chains, germinated with internal 
basidia instead of as they do, would this species be placed in the 
genus Gallowaya and in the group with Coleosporium ? Except 
for the proliferation of the binucleated cell formed after cell fusion 
in this Chrysomyxa, there is not very much difference between it 
and Gallowaya so far as the organization of the sorus is concerned. 
In both cases the fusing cells are topped by two or three sterile cells. 
A short chain of binucleated cells is developed after cell fusion. 
These cells clearly never function as spores; they remain binucleated 
to the end, representing a short sporophytic generation. Nuclear 
fusion occurs in the outermost cells, so that a drain of uninucleated 
teleutospores is formed. Lindfors (IS) doubts very much whether 
all of the uninucleated spores function in this Chrysomyxa, since in 
some cases the lower ones seem to lose most of their cytoplasm and 
become elongated. This is what often occurs in Gallowaya. In 
discussions of morphology it is not a question whether a structure 
functions, or whether a spore germinates, or what form the germ 
tube takes, but it should be asked, What are its phylogenetic ante¬ 
cedents ? 
Regardless of the merits of Grove’s contention that Ochropsora 
is not one of the Coleosporiaceae, there can be no question that a 
system of classification based on the manner of spore germination 
is not a natural one. The writer (7) has shown that in certain strains 
of Caeoma nitens some of the aecidiospores produce long germ tubes 
which reinfect the host locally so that eventually teleutospores 
appear in the life cycle, while other aecidiospores, even from the 
same sorus, produce promycelia directly. So long as an unstable 
condition exists, such strains of orange-rust of Rubus can not be 
separated generically. 
Galloway (10 , p. 448 ) says: “The entire contents of the cell seem 
to be used up in the formation of the promycelium (sterigma) and 
the sporidium, and if this is not the case, the formation of secondary 
sporidia goes on until there is no protoplasm left.” W. W. Diehl 
has informed the writer that he has seen cases where more than one 
sporidium was formed on the cell outgrowth in Gallowaya. Pos¬ 
sibly in rare cases a true external promycelium is formed in Gal¬ 
lowaya. The writer has not seen young spores of this form with 
more than two nuclei. After germination, however, one can fre¬ 
quently find basidial cells with two bodies, as noted previously, both 
