Box. —Vol. II. ] B YXBEE— LA VA TERA . 65 



The pollen-mother-cells are large, and the diameter of the 

 nucleus is equal to fully one-half that of the cell. The 

 chromatin thread is thick and stains blue with gentian 

 violet. The largre nucleolus stains red with safranin. It 

 contains a single vacuole. The linin either forms a complete 

 network filling the whole nucleus, or is present as broken 

 threads attached to the chromatin and nucleolus. In neither 

 case does it stain. 



The cytoplasm is made up of two constituents, one fibrous, 

 the other granular. The fibrous part forms a network com- 

 posed of delicate threads crossing each other in every 

 direction. These threads stain deep blue with gentian 

 violet. The other element is composed of small granules, 

 varying somewhat in size. 



These granules are scattered throughout the network, 

 both between and upon the fibers, usually in sufficient quan- 

 tity to give the cytoplasm a cloudy appearance. They have 

 a tendency to collect in small, denser masses at the inter- 

 section of the fibers of the network. This tendency is 

 especially noticeable in the earlier stages. A little later the 

 granular matter is distributed more evenly. It stains a 

 brownish yellow with orange "G". A cell in this stage is 

 shown in fig. i. 



The first change that occurs in the cytoplasm is the elon- 

 gation in a direction parallel to the nuclear wall of the row 

 of meshes immediately surrounding the nucleus (fig. 2). 

 This process goes on until three or four rows of meshes 

 outside the nucleus have become pulled out in this way (fig. 

 3). These meshes become so long and narrow that, often, 

 on casual inspection, there seem to be threads wound round 

 and round the nucleus. On close examination, however, 

 the meshes can always be seen. Within the nucleus the 

 linin network has meanwhile broken up somewhat; the 

 threads lose their smooth, transparent appearance and begin 

 to stain blue. One or more additional vacuoles appears in 

 the nucleolus, which begins to stain purple rather than red. 



Soon after this, the granular substance, which hitherto has 

 been equally distributed throughout the cytoplasm, begins 

 to collect in a denser mass immediately about the nuclear 



