2 10 
Hartog. — Recent Researches 
After this stage the lines of separation become clear, con- 
tract, and gradually round off, beginning at the angles; and as 
they contract they retreat from the sporange wall, which now 
shows a double outline. The front spore, as it retreats from the 
process, leaves the layer of hyaloplasma at the apex, and is 
only connected with it by one or two strings which are finally 
retracted into the spore, as the hyaloplasma from which they 
are drawn disappears or becomes confounded with the end 
wall. [My description would state that one or more vacuoles 
appear at the base of the hyaloplasma disk, and by their 
enlargement separate a terminal portion from the front spore, 
leaving one or two strings along which the hyaloplasma is 
retracted into the front spore.] Next appear the cilia, as slow 
outgrowths, at first short straight bristles, with simple oscilla- 
tions. The front spore has its cilia always at the front end 
next the process ; but there appears no polarity about the 
others. At the same time the spores manifest shaking 
(wackelnde) movements, increasing in strength till their dis- 
charge. 
During this contraction and development of the spores, 
they become warty, and some of the processes are abstricted. 
These lumps of protoplasm after independent movements are 
mostly absorbed (probably always) by the very spores from 
which they were separated ; a few may be unabsorbed, pass 
out with the spores and undergo diffluence ; but this makes 
no difference to the spores themselves. Rothert recalls similar 
processes described by De Bary in the formation of the 
oospheres. The mature zoospores now contain three vacuoles, 
of which at least one, that at the front end, contracts rhyth- 
mically. [I have seen in Achlya at this stage all three vacuoles 
rhythmically contractile.] 
On treatment with iodine about a quarter of the protoplasm 
turns dark brown, and contains black granules just below the 
surface. Nothing of this shows in the fresh state, nor is there 
any polar relation of the dark portion to the axis of the spore. 
Rothert suggests no explanation ; it seems to me that we may 
fairly refer the browning to glycogenic contents to be used 
