648 
Journal of Agricultural Research 
Vol. XXIV. Na 8 
fairly characteristic spores in a dense racemose cluster. Sporophores 
thus produced may show a tendency to branch, not usually observable 
in material collected in the field. 
A process quite analogous to germination may be observed in the 
proliferation from the spores of Helminthosporium gramineum, of short 
sporophores in the regions where ordinarily germ tubes appear. These 
bear a variable number of secondary spores that may usually be dis¬ 
tinguished from the primary spores by their smaller dimensions. When 
this takes place while the latter are still attached to the sporophore, 
the whole apparatus may bear a partial resemblance to an Altemaria 
fructification. A somewhat similar condition appears to obtain quite 
normally also in H. catenarium, the fungus parasitic on wood reedgrass 
{Cinna arundinacea L.), where, however, the secondary spores more 
often are borne directly at the tip of the primary one, which thus comes 
to bear two hila. When grown in culture, this species develops ramif)dng 
fructifications in which a series of spores alternating with short sporo- 
phoric hyphae bear short sporophoric processes from the end cells. In 
fructifications of this type, the distinction between sporophore and 
spore is at least partly obliterated, the two types of structures merging 
into one another. This miscellaneous type of growth may be observed 
when H, teresy H. cyclops, and even H, sativum are grown on artificial 
media. This growth is apparently encouraged by moist conditions, 
although, as has been indicated, it appears to occur in nature in the case 
of H. catenarium and H. gramineum. 
It may not be out of place to mention a peculiarity in the growth of 
the mycelium of most species of Helminthosporium which, although 
perhaps not confined to this genus, may not be without sigmficance. 
If, for example, a number of spores of if. bromi are mounted in water 
and two come to lie in contact with each other, it will be seen that usually 
one or more pairs of germ tubes are proliferated from approximately 
opposite positions and immediately anastomose, thus uniting the two 
spores by several short hyphal connections. (PI. 8, Dc.) This tendency 
toward anastomosis is expressed even more strongly in the mycelium 
that develops somewhat below the surface of agar cultures, and may be 
studied conveniently by cultivating the fungus on poured plates, the 
anastomosis occurring abundantly near the lower siirface of the agar. 
Some of the cells involved in these hyphal fusions swell into subglobose 
bodies and proliferate short irregular processes of inflated segments, the 
whole resulting in small, dark brown, knotty masses of mycelium, ^me 
of these continue to increase in size, developing into the subspherical 
sclerotia, readily visible to the naked eye, the profuse occurrence of which 
in culture is a distinguishing mark of this species. Although the writer 
has not succeeded in cultivating these sclerotia further, there can be 
little doubt that they represent immature perithecia, as they are entirely 
similar to the immature perithecia found on leaves of the natural host 
in fall. The inference is further strengthened by the fact that other 
species of Helminthosporium, H. teres and H. triciti-repentis, of which 
ascigerous conditions are known, show these structures in abundance. 
The writer is inclined to believe that in whatever species such sclerotia 
or abundant anastomoses (resulting in the production of complexes of 
lobulate segments) are found to occur, perithecia may be sought with 
considerable prospect of success. 
