48 McCLUNG. 



andern ausser 1 1 chromatischen Elementen auch noch ein ein- 

 zelnes zuletzt ungetheilt gebliebenes Chromatinelement, welches 

 wahrscheinlich als Nucleolus anzusehn 1st." 



14. The investigations of Toyama ('94) upon Bombyx and 

 several other Lepidoptera, like those of Platner, do not afford us 

 any very definite idea of the accessory chromosome in this order. 

 Several references to nucleoli are made, however, and these I 

 will quote : 



15. "The nucleolus (first spermatocyte), lying either in the 

 chromatin mass or outside of it, persists, as is unusual in skein 

 stages of other animals, till to the end of the skein stage shortly 

 to be described. . . . The nucleolus, however, shows no change 

 from the first resting stage till the present stage, and always con- 

 sists of small chromatic granules imbedded in a less stainable 

 matrix. 



16. " In a still later stage the chromatin granules again com- 

 mence to separate from one another, and the nucleus again pre- 

 sents the appearance shown in Figs. 31 and 32. In most cases 

 two nucleoli are found in the nucleus of this stage. These grad- 

 ually migrate toward the periphery of the nucleus facing the 

 center of the cyste (rarely, facing the wall of the cyste) and are 

 finally pushed out into the cytoplasm one after the other through 

 the nuclear wall at this point. Placed in the cytoplasm the 

 nucleoli seem to change their quality, since they now stain dif- 

 ferently from what they did when they were in the nucleus. This 

 is shown by the use of Hermann's triple staining, by which the 

 nucleolus in the cytoplasm takes a brownish color, while it 

 colors deep red so long as it is within the nucleus. The further 

 fate of the nucleoli in the cytoplasm is not known. 



17. "In this stage I have not found any nucleolus in the 

 ' Kernplatte,' while Henking observed it in a spermatocyte of 

 Pyrrhocoris aptcnis. ' ' 



1 8. Wilcox ('95) in his studies upon Caloptenus femnr-rubrum 

 and Cicada tibiccn finds peculiar nucleolar structures which will 

 be found described in the following excerpts : 



19. "Cytoplasm and achromatic nuclear parts were stained 

 green, the chromosomes, nucleolus, and centrosomes red (safranin 

 and victoria-green). ... In some stages the chromosomes were 



