Cloisterium Moniliferum 



F. M. Andrews. 



Specimens of Closieriuin inoniliferum were centrifuged }>y simply placing 

 a quantity of the plants in a small amount of water in tlie glass cylinders. 

 A large number of the specimens were easily obtained by filtering a consider- 

 able volume of water containing the plants through filterpaper. As the speci- 

 mens lie in different positions the centrifugal force acted in a great many 

 directions on these unicellular plants. The contents was therefore thrown 

 sometimes to one end, at other times to the side or diagonally in the cell 

 according to the direction tlie centrifugal force had acted. 



A centrifugal force of 1207 g. acting for J minute is enough to displace 

 the contents of the cell of Cloderium moniliferum. The contents are displaced 

 all along the walls almost to the centrifugal end of the cell, while in the center 

 it remains in a string-like mass about two-thirds the length of the cell 

 The chlorophyll, as well as the gypsnm particles, which latter showed the 

 Brownian movement actively, were also displaced. A complete return of 

 the cell contents took place at 22° C. in 3 days. Movement of the protoplasm 

 can be clearly seen in Closlerium moniliferum in the normal condition. As 

 soon as the centrifugal machine could be stopped and the specimens examined, 

 which was about two minutes, there could be seen an exceedingly rajjid move- 

 ment of the protoplasm in all directions. Part of the contents was forced 

 very compactly into the centrifugal end of the cell. The movement was not 

 visible before centrifuging, but was observable immediately after. There 

 was shown a very beautiful arrangement of transparent polygons! protoplas- 

 mic plates so placed as to resemble a honeycomb. This same phenomenon 

 I have observed in the cells of seeds of Phaseolus mxdtiflorus when they had 

 been allowed to germinate and were then centrifuged. 



The cells were rarely killed by centrifuging and by the displacement of 

 their contents. Unless accidentally killed the contents always returned sooner 

 or later to its original position. Tliis proceso began by a sprea ding out on all sides 

 of the centrifuged mass. This at first was very slow, but gradually became 

 more rapid. By the end of the first day at 22° C. only about one-tenth of 

 the area of the cell, from which the contents had been displaced, had returned. 

 On the second day about one- third of the displaced area was recovered and, 

 as stated before, the contents had retm-ned to all parts of the cell by the end 

 of the third day. The contents as they spread out were not of the usual density 

 but gradually became so as its return progressed. The return of the contents 

 was materially assisted in its redistribution bj' the rapid streaming movements 

 of the protoplasm above referred to. The gypsum crystals also eventually 

 returned to their former position in the cell although they, like some other 

 parts of the cell contents, were carried for a while in all directions by the mov- 



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