THE ENDOSPERM 



173 



appear many nuclei are always enclosed in each cell and sub- 

 sequently fuse. In this particular case the free nuclear divi- 

 sions are often irregular, and of course the number of chromo- 

 somes is exceedingly variable, a fact very common in all endo- 



B 



F IG . 78. — Advanced stages in development of endosperm. A, Reseda odorata, upper 

 part of figure showing free nuclear division, while in lower part nuclear division is 

 accompanied by formation of cell walls; x 860; £, Caltha palustris, showing all 

 nuclear divisions accompanied by formation of walls, x 155; C, Corydalis cava. 

 showing free nuclear division within cells of endosperm; D, the same, showing 

 multinucleate endosperm ; x 860. — After Strasbvkger. 4 



sperm. The same phenomenon was observed by Humphrey 17 

 in Carina indica, in which the parietal layer of free nuclei 



block " containing several 



becomes blocked out by walls, each 



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