64 BOTANICAL MICROTECHNIQUE. 



into globular masses which dissolve in 10$ acetic acid with 

 the formation of bubbles. 



e. Calcium Malate, Ca(COO) a .CH,.CHOH. 



95a. Calcium malate is thrown down in large quantity by 

 alcohol in the stipes of the fronds of Angiopteris evecta^ 

 according to Belzung and Poirault (I). It often forms^ 

 prisms of considerable size, which belong to the rhombic 

 system, and are with difficulty soluble in water, but readily 

 so in acids. With sulphuric acid they form needles of 

 gypsum. On heating on platinum foil they are first black- 

 ened, then show a striking increase in volume, and are 

 finally converted into pure white lime. On being heated 

 in the reducing flame they give off the characteristic odor 

 of succinic acid. By the aid of Borodin's method it may be 

 shown that they are completely insoluble in a saturated solu- 

 tion of neutral calcium malate. 



f. Calcium Phosphate, (CaO 3 ) 3 (PO) 2 ? 



96. Calcium phosphate has been observed only in solu- 

 tion in the cell, except in case of globoids (cf. 388) and of 

 a single instance which requires confirmation (cf. Nobbe 

 Hanlein and Councler I). It separates in the form of beau- 

 tifully formed sphaerocrystals in the interior of many parts 

 of plants, after they have been placed in absolute alcohol ; 

 for instance, in the stems of Euphorbia caput-medusce and 

 Stapelia picta, as well as in the stalk of the frond of Angi- 

 opteris evecta. These sphaerites are usually formed only 

 after a considerable time (weeks or months).* 



They have usually a yellowish or brownish color and are 

 very slowly soluble in cold water. In hot water, too, they 

 are only dissolved after a long time ; at least, the solution of 

 large sphaerites was not complete after several minutes, when 

 they had been heated to boiling in water on the slide. 



With ammonia they behave as with water; they are only 



* I have lately found globular or clustered bodies consisting at least 

 chiefly of calcium phosphate in the living epidermal cells of a species of 

 Cyperus (cf. Zimmermann VI, 311). 



