22 



Myxophycese 



a peristaltic manner, or (2) the plant has some propelling organs such as 

 flagella, cilia or pseudopodia, that either act upon the solid substratum 

 or move freely through the water. One must agree with Phillips that 

 the first of these possible explanations is quite inadequate to account for 

 all the movements exhibited by the Oscillatoriacea?. The second hypothesis 

 is, however, at present unsupported by sufficient testimony for it to be 

 accepted with any degree of confidence. 



In certain species of Oscillatoria and Phormidium there have been 



described fine hair-like outgrowths from 

 the terminal cells (see fig. 14). These 

 have been regarded by many observers 

 as parasitic or saprophytic Bacteria of 

 the nature of Opliiotlirix, but Phillips 

 ('04, p. 320) asserts that those out- 

 growths observed by him were living 

 portions of the algal filament which 

 had grown out from the cell-protoplasm. 

 He was unable to assign a definite 

 function to these outgrowths, which he 

 states at first stain like the protoplasm 

 of the terminal cell, but afterwards 

 react in the same manner as the cell- 

 walls. He considered that they pro- 

 bably acted as tactile organs in 

 piloting the trichome around obstacles, 

 but that they were not the cause of 

 the movements. These filaments were 

 also found in Cylindrosperinum (fig. 10). 



Phillips states that by using Bunge's mordant, followed by carbol-fuchsin, a method 

 which brings out the cilia of Bacteria very well, he was able to demonstrate the presence 

 of fine cilia along the sides of the trichomes (see fig. 14). These cilia were very short, and 

 could only be seen with extreme difficulty in the living organism. He considers that the 

 reason they have been overlooked by other observers is that they ' mass down when 

 placed in reagents and appear as granules of foreign substance on the exterior of the 

 trichome.' He also concludes that the presence of these cilia ' explains more clearly the 

 moving of the pai-ticles of indigo along the trichome as described by Schulze and others, 

 and the massing down of the cilia will explain why the contour of the trichomes is so 

 rough oftentimes, as is especially shown when stained with Heidenhain's iron-ammonia- 

 alum hsematoxyliu, with but slight or no destaining.' 



It seems scarcely possible to accept Phillips' conclusions that the creeping movements 

 of the Myxophyceee are caused by very delicate, short cilia without much confirmatory 

 evidence. Such confirmation is essential if only because Phillips' statements regarding the 

 structure and division of the ' central body ' are not in agreement with the most reliable 

 cytological work done on the protoplasts of these plants. 



Fig. 14. Portions of filaments of Oscilla- 

 toria showing the hair-like outgrowths 

 from the end-cells, and also the lateral 

 cilia described by Pbillips. Highly mag- 

 nified (after Phillips). 



