350 



BOTANICAL GAZETTE 



[NOVEMBER 



tibly, the middle portion becoming clearer and assuming a 

 zigzag outline (_/?^. 6), between which and the periphery of the 

 grain a number of crystalloidal lamellae arise {^fig^ 7) ; the 



2« 





.' .V' 



fc. "1*, ,-' / 



25 



31 



34 



Figs. 23^34. — Corn starch grains, showing the effect of chromic acid and 

 other swelling reagents. 



grain now becomes spherical and marked by a number of con- 

 centric lamellae near the periphery; the latter finally ruptures 

 {fi^- ^) and then follows a gradual solution of the grain, the 

 peripherical la^^er sometimes recurving like the cutin layer of 

 an epidermal cell on treatment with sulphuric acid {figs, g, 10). 



s 



\ 



