210 



BO TA NIC A L MICRO TECHNIQ UE. 



'flower of Funkia, Ornithogaluin, Agave, Draccena, and others 

 \(cf. Zimmermann VI, 185). 



367. For fixing the elaioplasts Wakker recommends es- 

 pecially a concentrated aqueous solution of picric acid. He 

 obtained a beautiful double staining of sections fixed with 

 this fluid by using aniline blue and alcannin in the fol- 

 lowing way. He added alcanna tincture in drops to a dark 

 blue solution of aniline blue in water, until the fluid had 

 taken a dark purple-red color, like that of haematoxylin. 

 He left the sections 20 hours in this mixture and then ex- 

 amined them in glycerine. The protoplasm was then light 

 blue, the nucleus and chromatophores dark blue, the oil a 

 fine red, and the elaioplast dark purple. These colors keep 

 for a long time in neutral glycerine-gelatine. 



368. Wakker (I, 482) includes among the elaioplasts also 

 the oil-bodies of the Hepatica, first described by Pfeffer 

 (VI). He was able to show by abnormal plasmolysis with 

 a 2of solution of saltpeter (cf. 432 and 436) that these 

 always lie in the protoplasm. To render the protoplasmic 

 wall of the oil-bodies visible, Wakker recommends, besides 

 the dilute alcohol used for the purpose by Pfeffer, a concen- 

 trated aqueous solution of picric acid. In this case the 

 access of the acid must be followed with the microscope, 



since a flattening of the protoplas- 

 mic wall of the oil-body usually re- 

 sults from its long action. 



369. The fat-bodies and oil-bodies 

 described by Radlkofer (I and II), 

 Monteverde (I), and Solereder (I) 

 are perhaps related to the oil-bodies 

 of the Liverworts. They have been 

 observed by these authors in the 

 palisade and spongy parenchyma of 

 various members of the Cordiacece, 

 Combretacea, Cinchonece, Sapotacece, 

 Sapindacece, Gramine^ Gaertneracece, 



17-17- <-r>i 11 



and Rubtacece. They usually occur 

 singly in each cell, and have always about the same size in 



chloroplasts: 



oil-drops. 



nucleus; o, 



