RELATION OF THE TRUE NUCLEOLUS TO THE LININ 



NETWORK IN THE GROWTH PERIOD OF 



PSELLIODES CINCTUS. 1 



WILLIAM M. GOLDSMITH. 

 (THIRTY FIGURES; Two PLATES.) 



INTRODUCTION. 



The purpose of the present line of investigation is to follow 

 the nucleolus in its relation to the other parts of the cell. Except 

 for the extended review and observations of Montgomery ('98), 

 the work on the true nucleolus is scattered in small bits through- 

 out the cytological literature from the first observations of 

 Frontana (1781) to the present time. Especially since the dis- 

 covery of the sex-chromosomes has the literature on this subject 

 been of a fragmentary character, consisting usually of a few 

 records here and there in papers dealing with other subjects. 



The work on the true nucleolus has been greatly retarded 

 by the similarity of the staining reactions of different nuclear 

 bodies and also by the confusion of terms which various observers 

 have used to indicate these nuclear bodies which have an affinity 

 for acid tar-colors and other plasma stains. Ogata ('83) was 

 the first to use the term "plasmosome" with reference to the 

 true nucleolus. The term "paranuclein" of O. Hertwig ('92) 

 and "pyrenin" of Schwartz ('87) are ofttimes erroneously applied 

 to the plasmosome itself, rather than to the substance of the 

 same. Eisen ('98) used the term "linoplast," since he insists 

 that the function of this body is to supply and nourish the linin 

 network during mitosis. To prevent further confusion, I shall 

 use the older and more familiar term, "nucleolus." The term 

 "nucleolus" however carries with it no definite meaning and 

 thus should not be used without a modifying adjective, either 

 expressed or implied, as the cytological literature contains many 

 errors and misconceptions on account of the lack of a clear dis- 



1 Contribution No. 152 from the Department of Zoology, Indiana University. 



121 



