Ohara : On the Mucilage of Hydrangea Paniculata, Sieb, j ^q 



cellular cavities formed by the surrounding cells. So the crystal-containing cell 

 assumes, in the cross section of the stem, a polygonal shape. 



As the crystals in the cell take the form of Raphides, each cell elongates in 

 one direction ; and, when found in the stem, it lies parallel to the long axis. 

 According to HOLLE's-^ statement, these raphides-containing cells occur 

 throughout the tribe Hydrangae and are regarded as one of the characteristics 

 of this tribe. Raphides are enclosed by a thick, homogeneous, sometimes brown- 

 coloured, transparent mucilage. SAWAMURA ^^ once analyzed the mucilage 

 and recognized in its hydrolized products galactose and arabinose. By my ex- 

 periment, it shows microchemically the following reactions : 



. i). With Delafield's haematoxylin, with safranin and methylen blue more 

 easily it can be stained. 

 2). With ruthenium red it is stained intensely red. 



3). By the following reagents no reactions can be obtained ; (a) Iodine 

 solution, (b) Zinc chloride iodine, (c) Iodine and sulphuric acid, (d) 

 Congo red. (e) Phloroglucin and hydrochloric acid. (f) Millon's 

 reagent. 

 4). By the lead subacetate wdiite precipitates can be obtained. 

 5). By the ammoniimi copper oxide solution it can not be dissolved. 

 6). In the water first it swells and then totally disappears, a proof of complete 

 dissolution. 



And the extract of the thin slices of the bast got by boiling them in water 



can be precipitated by adding some strong alcohol. After boiling the extract in 



diluted hydrochloric acid, it reduces the Fehlings solution, although the extract 



shows no reaction whatever before its treatment with the acid. By the reactions 



above stated it can be concluded that the mucilage belongs to the pectin com- 

 pounds. 



From the economical point of view, it is not unnecessary here to describe 

 how the raphides-containing cells are distributed in a plant body, so that those 

 who are interested in the matter may teil what part of the plant is most richly 

 endowed with the mucilage. The following results obtained by my observation 

 may serve as a suggestion to this point : — 



2) HoLLE ; Beitrage zur Anatoniie der Saxifragaceen und deren Systematik. Botanisches Central- 

 blatt. 1893. 



3) Savvamitra ; in the Manufacture of Japanese paper' by YoSHii. (In Japanese) 1897. 



