RELATION OF TRUE NUCLEOLUS TO LININ NETWORK. 13! 



whole thread presented the appearance of a row of granular 

 bodies with only here and there a fibrous connection (Figs. 7 

 and 8). 



As the chromatin threads begin to elongate after the synaptic 

 stage, the chromatic area as a whole begins gradually to stain 

 less intensely until the stage represented in Fig. 7 is reached, 

 when, in good preparations, nothing can be observed except the 

 large nucleolus, surrounded by faint traces of fibers and a large 

 number of granules. This gradual decrease in the staining 

 capacity of the chromatin material rendered the tracing of the 

 various transitional stages very difficult. Although the evidence 

 was not entirely conclusive, the most careful observations sug- 

 gested that the granules found in this and later stages were 

 formerly a part of the chromatin threads and are distinctly 

 chromatic in nature perhaps being either a part of the true 

 chromosomes or directly related to them. 



Throughout the early growth period, no traces of a nuclear 

 wall has been observed. In many and perhaps the majority of 

 cells, the chromatin threads and granules seem to have a definite 

 limiting space. However, among the same and in other cells, 

 innumerable instances can be found in which the granules and 

 granular rows are continuous far beyond what could be considered 

 the nuclear area (Figs. 8 and 9), thus indicating the non-existence 

 of a nuclear membrane. Flemming in the blood cells of Amphib- 

 ians, Hertwig in the sperm-mother-cells of Nematodes, and other 

 more recent workers have referred to the difficulty involved in the 

 demonstration of the presence of a nuclear membrane in certain 

 stages of cell growth. 



The granules are now found scattered indiscriminately through- 

 out the entire cell. The natural growth of the nucleolus .and a 

 simultaneous enlargement of the surrounding clear area, causes 

 these granules to be crowded together between the nucleolus 

 and the cell wall, forming a more or less incomplete circle around 

 the nuclear area (Figs. 10 and u). As more and more granules 

 are added to the circle, visible strands of linin can be noted 

 between them. The next stages (Figs, n, 12 and 13) are char- 

 acterized by a gradual decrease in staining capacity of the larger 

 granules, simultaneously with a continued increase of the inter- 



