CIRCULATION OF PROTOPLASM. 



39 



if the anther is previously removed. In this latter case the quan- 

 tities of air clinging amongst the hairs will give trouble, and 

 it takes some pains to remove them. This is best effected 

 by means of a fine camel-hair brush, with which the hairs are 

 brushed over from below upwards, the tuft being at the same 

 time held firmly at the base. After this the cover-glass is laid 

 on. Most of the hairs will not have suffered, provided the air 

 has been removed with sufficient care. 



The hairs in question are formed of numerous barrel-shaped 

 cells, arranged in an unbranched series. At the points of con- 

 striction lie the partition walls which separate adjoining cells 

 from one another. Each cell (Fig. 14) shows a thin 

 continuous lining layer of protoplasm or cytoplasm, 

 and is traversed in the interior by numerous thin- 

 ner and thicker protoplasmic (cytoplasmic) strands. 

 Suspended within these strands is to be found the 

 nucleus, surrounded by an enveloping layer of cyto- 

 plasm (shown somewhat below the middle in the 

 figure). The cell cavity in which the nucleus is 

 suspended, and which is traversed by the cytoplasmic 

 strands, is filled by a violet-coloured cell sap. It is 

 the vacuole, The cytoplasm consists in a colourless, 

 viscous, semi-fluid substance, which is distinguished 

 by the name of Hyaloplasm (i.e., clear plasma), and 

 which contains numerous minute granules, known 

 as Microsomata, or Microsomes, The microsomes 

 have various reactions ; some of them are solid bodies, 

 others are vesicular, having a fluid, highly refractive, 

 content surrounded by a skin of plasm. Besides 

 these there can also be seen in the protoplasm, in 

 greater or less number, somewhat larger, highly 

 refractive bodies, which appear somewhat bluish in 

 colour, and which will be designated by the terms Starch-formers 

 or Leucoplasts. If we focus the microscope upon the cytoplasmic 

 lining layer, it will be seen that this is not in movement as a 

 whole, but rather that fine, net-like, anastomosing, cytoplasmic 

 streams course about within it. In the cytoplasmic threads 

 which traverse the cell-cavity the movement is especially 

 strong. These streams are of varying thickness, they anasto- 

 mose laterally with one another more or less frequently, and 

 the nucleus manifestly furnishes a central point for them. 



FIG. 14. A 

 cell from the hair 

 on the filament 



