Cytology and Movements of the Cyanophycee. 321 
tried, but without marked success. Aside from a decided 
roughness of the outer contours, nothing could be seen 
for a long time. The long hair-like trichomes which pass 
out from the walls of the heterocysts and spores of Cylindro- 
spermum had been seen, but they did not have the proper 
movements to cause the entire motion under investigation. 
By Gardiner’s corrosion method with iodine and sulphuric 
acid, I was able to plasmolize the protoplast of the spore of 
Cylindrospermum and the trichome of Oscillaria very 
greatly (Figs. 27 and 63), so that the shrunken protoplast 
showed very plainly a number of finger-like processes that 
passed out through the spore walls and became continuous 
with these hairs. The corrosion had so swollen the cell wall, 
that the minute pores through it were very evident. These 
hairs, then, are not parasitic organisms as supposed by 
Hansgirg, though they did not seem to cause the motion 
of the plant except, probably, to determine the direction in 
which the plant would move, or to cause the forward end 
to avoid an encountered obstacle. 
Remembering that the spores and heterocysts of these 
plants are but modified vegetative cells, it is easy to per- 
ceive that these pores through the spore wall must have 
been present in the vegetative cell, though difficult to demon- 
strate. This I was able to show, and the long hair-like 
appendages, which Hansgirg had supposed to be parasitic 
organisms, are in reality, stronger growths of the fine cilia 
which cover the sides of the trichomes. The spores finally 
lose their hair-like appendages and the pores become closed 
through the thickening of the wall. Realizing that the cilia 
along the sides must be very delicate, I employed methods 
of staining which are used to demonstrate flagella on the 
bacteria. By the use of Bunge’s mordant, followed by 
carbol fuchsin, which brings out the flagella of the bacteria 
very nicely, I was able to demonstrate that the roughness 
of contour which I had noticed with other stains, was in 
reality caused by tiny protoplasmic knobs (Fig. 40) which 
