200 CALIFORNIA ACADEMY OF SCIENCES. [Proc. .^d Ser. 



EXPLANATION OF PLATE XXXVIL 



The Abbe camera was used in drawing. 



Objective, Zeiss, oil immersion 1/12; ocular, compensating No. 6. 



Fig. I. Represents a cell with the chromatin in the spireme stage. The 

 cytoplasm is composed of two distinct elements : One is fibrous 

 and forms a reticulum throughout the cell from nuclear wall to 

 cell-wall. The other is granular and is uniformly distributed 

 within and upon the meshes of the reticulum. The meshes of 

 the reticulum are irregular in form and are smaller immediately 

 surrounding the nucleus than elsewhere. Its threads are sinuous 

 and irregularly knotted. The nucleolus is large and contains a 

 small vacuole. 



Fig. 2. The cytoplasm exhibits a peculiar structure. The fibers of the re- 

 ticulum immediately about the nucleus are drawn out into long, 

 narrow meshes parallel to the nuclear wall, forming a sort of 

 weft about it. These appear, at first glance, as long, continuous 

 fibers wound about the nucleus. 



Fig. 3. The meshes of the cytoplasmic reticulum are drawn out at right 

 angles to the nuclear wall and appear as if radiating from the 

 nucleus. The chromosomes are very near the nuclear wall. 

 The nucleolus is still about as large as that in fig. i and contains 

 several vacuoles. Linin granules and threads partially fill the 

 nuclear cavity. 



Fig. 4. The granular element of the cytoplasm is beginning to accumulate 

 in dense masses. Deeply staining, irregular strands are to be 

 seen in the cytoplasm. They are radially arranged and some of 

 them extend clear to the cell-wall. At first glance they appear 

 as free fibers, but close examination shows them to be only 

 thickened, more granular strands of the cytoplasmic reticulum. 

 In other respects the figure resembles fig. 3. 



Fig. 5. Three or four conical groups of fibers extend from the nuclear wall 

 into the cytoplasm. Otherwise the figure is very much like 

 fig. 4. 



Fig. 6. The deeply staining, radially arranged, cytoplasmic strands seen in 

 figs. 4 and 5 are less marked. There is a good development of 

 linin. The chromosomes are very near the nuclear wall, which 

 is irregular in outline and is beginning to be transformed into a 

 meshwork. 



