On two species of Heterospornim particularly Heterosporium echinulatum f f 
creased in length, and became septate (fig. 4, 5), but did not produce 
side branches until they had attained a considerable length (100—200 fi). 
Their course was nearly straight Soon after the appearance of the first 
germ hyphae, others made their appearance, to the number of four 
(fig. 5). Their position was at the end of the spores a little to one side 
of the long axis. A germinating spore from which 4 germ hyphae had 
grown, presented the appearance of an x, the spore being in the centre 
of the x (see fig. 5). This appeared to be the usual method of germi¬ 
nation; in some cases, however, only 3 germ hyphae were produced, 
(fig. 3 a), taking up the end positions, or sometimes 2 of the 3 germ hyphae 
were observed to come from the central portion of the spore (see fig. 3 b). 
One case was noticed in which 5 germ tubes had been produced, the 
extra hypha came from the middle of the spore (see fig. 3 c). After 
having attained a length of 100 ja the hyphae became septate. 
In normal PASTEUR-solution the same x shaped growths were 
produced, but not to such an extent as in the solid media. In tap-water 
the spores generally produced two hyphae, one at each end of the spore, 
almost exactly opposite the ends of the long axis (fig. 2). The hyphae 
grew greatly in length, and finally became septate, the individual cells of 
the hyphae being generally longer than those produced on solid media. 
One case was observed in which two other germ hyphae began to be 
formed some days after the appearance of the first. In no case were 
the hyphae of these water cultures seen to branch. In some cases a 
small conidiophore was produced after a week, directly from the old 
germinating spore. After 24 hours growth upon solid media the x shape 
produced by the germinating spores was no longer recognisable. The 
germ hyphae had repeatedly branched to form mycelia fairly uniformly 
distributed over the agar surface. It will be seen that this was not the 
case with Heterosporium echinulatum. 
2. Origin of Conidiophores. 
After 3 days growth the small colony consisted chiefly of radiating 
hyphae, which originated from the branching of the main (generally 4) 
germinating hyphae of the spore. The original spore could only with 
difficulty be made out. The centre of the colony appeared as a tangled 
mass of hyphae. The edges were composed of radiating hyphae, which 
had not as yet overlapped. These bore short branches, some of which 
were conspicuous by their colour and straightness, as compared with 
others which were not coloured. The distal end of the cell of origin of 
these coloured hyphae and the middle cells were coloured a greyish-brown. 
The actual growing tip was colourless (fig. 8). 
Up to this point nearly the whole colony was beneath the agar sur¬ 
face, as was proved by the fact that the cell walls were sharply defined, 
whereas walls of the original spore, and of some of the germ tubes 
which lay upon the surface of the agar were thick in appearance and 
shaded, showing them at once to be cylindrical structures. These latter 
appeared to be covered with a film of moisture. 
It was noticed that the tips of some of the uncoloured branches 
above-mentioned, were shiny and shaded, showing them to have reached 
the surface. The actual point of departure from the agar, was marked by 
