BOTANY: C. DRECHSLER 
223 
final extension. The majority of species show these tendencies combined in 
different ways. 
(6) The sporogenous hyphae of most species are coiled in peculiar spirals 
sometimes resembling the spores of the hyphomycetous genus Helicoon. 
These spirals exhibit pronounced specific characteristics in the number, diam- 
eter, and obliquity of their turns, and especially in the direction of rotation 
(whether dextrorse or sinistrorse). 
(7) Sporogenesis, where it can be followed, begins at the tips of the fertile 
branches and proceeds basipetally. In the larger number of species the proc- 
ess involves the insertion of septa, which in certain cases, are relatively very 
massive, and in others, so thin as to be barely discernible. The disposition of 
these septa while the delimited spores undergo maturation processes, varies 
with the species: (1) they may remain more or less unaltered; (2) they may 
suffer a median split, the two resulting halves being then separated as the 
result of the longitudinal contraction of the young spores, leaving alternate 
portions of hyphal wall completely evacuated; (3) or they may first become 
considerably constricted and subsequently converted into non-stainable 
isthmuses connecting the mature spores. The apparent absence of septa in 
the sporogenous hyphae of other forms, is, perhaps, attributable to optical 
difficulties. 
(8) Granules are readily differentiated in the spores of many species, which 
possess the staining properties and uniformity of size characteristic of nuclei; 
they generally occur singly, but in the larger spores of a few forms, two are often 
found occupying diagonally opposite positions. 
(9) As in the vegetative thallus, metachromatic granules occur in the 
aerial mycelium, being very rarely found in spores or sporogeneous hyphae 
but becoming very abundant in degenerate sterile hyphae. 
(10) The older axial filaments of some species show marked distensions, 
which, in extreme cases, result in figures simulating Leptomitus. These arise 
as local distensions at the points of attachment of the more extensive lateral 
sporogenous processes. Cuneate modifications of the sterile axial filaments 
below the origin of branches, also occur. 
(11) Curious spherical structures appear regularly in some forms, both 
in the sterile axial hyphae, where they may contain either a median septum or 
a number of peripheral metachromatic granules, and in the sporogenous hyphae 
where they are associated with the regularly spaced septa. 
(12) The spores germinate readily in suitable solutions, producing from 
one to four germ tubes, the approximate number being more or less character- 
istic of the species. 
(13) Owing to the absence of any well defined bacterial characteristics, the 
writer is of the opinion that the view that Actinomyces represents a transition 
between the Hyphomycetes and the Schizomycetes, as well as the phylo- 
genetic corollary based upon it,, may safely be abandoned. If mere size is 
to be regarded as important, it would appear to be equally profitable to look 
