263 



THE MICROSCOPE. 



in thft filament, and which divide it into distinct joints 

 or cells. 



The presence of this cell-membrane may be best de- 

 monstrated by breaking up the filaments, either by moving 

 the thin glass cover, or by cutting through a mass of them 

 in all directions with a fine dissecting knife. On now 

 examining the slide, in most in- 

 stances many detached empty 

 pieces of this cell-membrane, with 

 its striae, will be found, as well 

 as filaments partly deprived of 

 the protoplasm, showing in those 

 places the empty, striated cel- 

 lulin coat. On the application 

 of iodine all these appearances 

 become unmistakably evident ; 

 the greater portions of the fila- 

 ment turning brown or red, while 

 the empty cells, with their striae, 

 remain either unaffected, or at 



Fig. 146. MesogUarermicularis most present a slight yellowish 



tint > as is frequently the case 

 with cellulose when old. 



With regard to the contents of the cell, the protoplasm 

 (or endochrome) is coloured in the Oscillator ice, and is de- 

 posited within it in the form of circular bands or rings 

 around the axis of the cylindrical filament ; iodine turns 

 them brown or red, and syrup and dilute sulphuric acid 

 produce a beautiful rose colour. As to their mode of pro- 

 pagation, nothing positive is known. If kept for some 

 time they gradually lose their green colour those exposed 

 to the sun, much sooner than others less exposed ; the 

 stratum eventually becoming brown, sinks to the bottom 

 of the vessel, and presents a granular layer, embodying 

 great numbers of filaments in all stages of decay.* 



The movements 01 the O&ciUatorice are indeed very sin- 

 gular, so much so that it is in vain to attempt to explain 

 them as altogether dependent on physical causes, and 

 equally so to show that they are due to a sarcode or animal 



* Dr. F. d'Alquen, "On the Structure of the Oscillatorise," Journal cj 

 Microscopical Science, voL iv. p. '245. 1856. 



