374 MONTGOMERY. [Vol. XV. 



wanders out of the nucleus into the cytoplasm, where it slowly 

 decreases in size. 



Hermann (-97) figures (Fig. 20) a spermatogonium nucleus of 

 Scyllium containing a single and a double nucleolus ; the latter 

 consists of two apposed spheres, which differ chemically and 

 dimensionally. 



Korschelt (-97) maintains his previous opinion ('96) of the 

 chromatin nature of the macrosomes of the nuclei in the 

 spinning glands of caterpillars, in answer to the criticism of 

 Meves ('97) (reviewed immediately below). Korschelt employed 

 the Ehrlich-Biondi stain with increased strength of the methyl 

 green, and thereby obtained a coloration of the macrosomes 

 and microsomes the very opposite of that procured by Meves. 

 " Ob man iiberhaupt achromatische, chromatische Substanz und 

 Nucleolen in alien Kernen so scharf auseinanderhalten kann, 

 wie dies vielfach geschieht, ist mir hochst zweifelhaft. Wenn 

 man in verschiedenen Zustanden der Kerne Nucleolen auf- 

 treten und wieder verschwinden sieht, wird man annehmen 

 miissen, dass sie sich aus den sogenannten achromatischen oder 

 chromatischen Substanzen des Kerns, vielleicht aus beiden 

 herausbilden. So konnen sich moglicher Weise auch die von 

 mir als Makrosomen bezeichneten Theile in Nucleolen umbilden 

 und das von Meves angegebene Auftreten von Vacuolen in 

 ihnen wiirde damit seine Erklarung finden." 



Meves ('97) contends that the microsomes in the spinning 

 glands of caterpillars, which Korschelt regarded ('96) as lanthanin 

 granules, are chromatin ; and what Korschelt regarded as chro- 

 matin granules (i.e., the macrosomes) are nucleoli. Meves 

 employed the usual formula of the Ehrlich-Biondi stain (Heiden- 

 hain's receipt), and finding that the macrosomes thereby become 

 stained red, concludes from this reaction their chromatin nature. 

 Stauffacher ('97) finds in the aster stage of the mitosis of one 

 of the pronephral cells of Cyclas, that the nucleolus still persists 

 intact in apposition to the spindle fibers. 



Wheeler ('97), maturation of the ovum of Myzostoma : this 

 object, previously described by the author ('95), is here more 

 fully described with the addition of figures. A remarkable 

 mode of formation of nucleoli in the pronuclei is described ; 



