Cytology and Movements of the Cyanophycecc. 321 



tried, but without marked success. Aside from a decided 

 rougliness 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 



