378 MONTGOMERV. [Vol. XV. 



methylen green. In mitosis, when the nucleus is uninucleolar, 

 the substance of this nucleolus becomes dissolved in the nucleus ; 

 when multinucleolar, however, one of the nucleoli may pass 

 out into the cytoplasm. Hesperus, " Pollenmutterzelle " : here 

 there is one nucleolus, which stains with methylen green, as does 

 the chromatic filament, and disappears in mitosis. Pisiutu, 

 same cells : here there is one hat-shaped nucleolus, which stands 

 in no connection with the " Fadenknauel "; " Sehr eigenthiim- 

 lich ist das Verhalten des Nucleolus in den die Kerntheilung 

 vorbereitenden Stadien. Anfanglich besteht derselbe aus 

 homogener, stark lichtbrechender Substanz. Spater sind am 

 Nucleolus eine dichte aussere und eine innere, bedeutend 

 schwacher lichtbrechende Schichte unterscheidbar. Endlich 

 findet man Stadien, auf denen neben dem noch unveranderten 

 Fadenknauel ein sehr schwach lichtbrechender Korper gefunden 

 wird, dessen Umrisse vollkommen demjenigen des ursprting- 

 lichen Nucleolus entsprechen " ; finally even this disappears. 



Zacharias ('82) studied the epidermis cells of Phajus, and 

 concludes that the nucleoli (one or two in number) consist of 

 plastin. They do not dissolve in distilled water ; swell with 

 .i/o nitric acid; do not stain with methylen green; and 

 dissolve in weak " Kalilaugelosung." 



Heuser ('84) studied the mitoses in the embryo sac of Fritil- 

 laria imperialis. In the resting nucleus there are from five 

 to nine nucleoli : " Dieselben sind intensiv gefarbt und stehen 

 in deutlich wahrnehmbaren Zusammenhang mit dem Nucleo- 

 Hyaloplasma." In the prophase of the mitosis they lose their 

 staining power and apply themselves to the chromatin threads. 

 He considers them, with Strasburger, " als Reserve-Behalter 

 der Kernsubstanz " (using the term " Kernsubstanz " as equiva- 

 lent to "Chromatin"); their ground substance consists of 

 plastin, permeated with chromatin. In Fritillaria, as well as 

 in Galanthus and Leiicojum, " fliesst das gesammte Kernkor- 

 perchen in die Kernelemente iiber, wahrend in anderen Fallen 

 ein Ueberschuss an Plastin als ' Secretkorper ' ausgeschieden 

 werden mag." 



Strasburger ('84), nuclei in the embryo sac of Fritillaria : in 

 the spirem stage the large nucleoli disappear, " wobei sich um 



