6o C. T. VORHIES. 



nucleus, and therefore probably has a functional part in the proc- 

 ess of secretion. The interesting question now arises as to 

 whether the material which thus increases for this purpose is 

 identical with the material which we believe to be the bearer of 

 the hereditary qualities, or whether it is of a different nature 

 functionally, but with the same staining reaction. This must 

 remain an open question. There seems to the writer no reason 

 why the same material cannot determine the direction of devel- 

 opment of the cell (/. c, carry hereditary qualities) and also de- 

 termine the functional activity of the cell after its differentiation. 

 In connection with the last two conclusions it may be well to 

 note that it has been repeatedly stated that in the process of yolk 

 formation in eggs, cytoplasm (yolk) is formed from substance 

 which is given off from the nucleus as buds (Blochmann, Scharff, 

 Balbiani), as extrusions of parts of the chromatin (Fol, Bloch- 

 mann, Van Bambeke, Erlanger, Mertens, Calkins), or as nucle- 

 olar substance (Leydig, Balbiani, Will, Henneguy) : also that 

 Miss Huie (1897) working on gland cells of Drosera, and 

 Mathews (1899) working on pancreas cells, got analogous 

 results with those secretory cells. 



University of Wisconsin, 

 Madison, Wis. 



LITERATURE. 

 Carnoy, J. B. 



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'04 Les Insectes. P. 463. Paris. 

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'97 Changes in the Cell-organs of Drosera Produced by Feeding with Egg-albu- 

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 Korschelt, E. 



'96 Ueber die .Struktur der Kerne in den Spinndriisen der Raupen. Archiv f. 



mikr. Anat., Bd. XLVII. 

 '97 Ueber den bau der Kerne in den Spinndriisen der Raupen. Archiv f. mikr. 

 Anat., Bd. XLIX. 



