METHODS OF SPECIAL STAINING ETC. 607 



Maige (C R. Soc. Biol, xcv, 1926, p. 299) studied amyloplasts 

 gradually turning green. 



1334. Pro-plastids. Potassium bichromate fixatives cause them 

 to elongate. Acetic acid destroys them ; later they become 

 resistant to this reagent. After osmification and silver impreg- 

 nation they appear hollow with a blackened periphery. See 

 KiYOHARA, Bot. Mag., Tokyo, xli, 1927, p. 211 ; Cytologia, i, 

 1930, p. 328 ; Weier, La Cellule, xl, 1931, p. 261 ; Zirkle, 

 Amer. J. Bot., xiv, 1927, p. 429. They form a system distinct 

 from the mitochrondia and are best seen in Benda fixed 

 preparations, 



1335. Pyrenoids show after Flemming and other common 

 fixatives. In material fixed in saturated alcoholic HgClg, 

 washed thoroughly and stained twenty-four hours in a 0-2 per 

 cent, solution of acid fuchsin, the pyrenoids are bright pink and 

 the nucleoli unstained. (See also § 1333.) 



1336. Elaeioplasts may be fixed like plastids. See Wakker 

 {Jahrb.f. Wiss. Bot., xix, 1888, p, 423), Fix in saturated aqueous 

 picric acid and stain in an aqueous solution of anilin blue that has 

 been turned purple by the cautious addition of alkanin. After 

 several hours the elaieoplasts show purple, cytoplasm light blue, 

 nuclei dark blue, oil droplets red. The colours last for a long 

 time in neutral glycerin jelly. 



