The embryo-sac of Aster Novw-Angliz. 
CHAS. J. CHAMBERLAIN. 
WITH PLATES XV AND XVI. 
In its early history the ovule of Aster Nove-Anglie pre- 
sents little to distinguish it from the well known types of Com- 
posite. Its anatropous character is already obvious, and its 
farthest from the re 9 is et but not always, des- 
tined to become the embryo-sac 
Development of the macrospore. 
In tracing the early stages in the development of the em- 
bryo-sac, I employed methods suggested by Auerbach’s re- 
searches,’ He emphasized the significance of the fact that if 
a preparation containing both spermatozoa and ova be stained 
with some combination like Biondi-Ehrlich, the nuclei of the 
spermatozoa take the green while those of the ova prefer the 
red. He proposed the terms, cyanophilous and erythrophil- 
ous to indicate these preferences. Since 1891 a few attempts 
have been made to obtain analogous results in plants. It is 
not very difficult to differentiate the nuclei of the pollen grain. 
he generative nucleus takes the green while the vegetative 
prefers the red, but I was not able to find a single green nu- 
cleus in the embryo-sac. The mother cell of the embryo-sac 
and also the four cells resulting from its division, stain red. 
At the first division of the nuclei of the embryo-sac the result- 
ing nuclei stainred. It might be noted, however, that the nu- 
* AUERBACH, LEopotp:—Zur Kenntniss der thierischen Zellen Sitzungsb. der 
Kgl. Preuss. Akademie der Wissenschaften, 26 Juni, 1890, and *‘Ueber binen 
sexuell ensatz in der Chromatophilie der Keimsubstantzen,"’ in the same 
journal of 25 Juni, 1891. 
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