Pammel — Anatomical Characters of Seeds of Leguminosae. 101 



the same as Mattirolo has described for Tilia or Kayser for 

 Ipomoea, that these and other writers have been mistaken in 

 their conclusions. I have therefore compared the Malpighian 

 cells of the orders Tiliaceae, Sterculiaceae^ Malvaceae, Cucur- 

 hitaceae, Labiatae, C onvolvulaceae , Rhamnaceae, Geraniaceae, 

 Nymphaeaceae, Sciiamineae, and Marsiliaceae with those of 

 Leguminosae, So far as possible I have taken representatives 

 of the orders heretofore studied. 



Tiliaceae. (Mattirolo 401, 10. Brandza 26, 115-116.^/. <S'. 

 f, 6-7). In a nearly mature seed of Tilia heterophylla two 

 rather wide light lines occur, one a little above the expanded 

 part of the cell-cavity, the other beginning near the end 

 of the Malpighian cell. When treated with chlor-iodide 

 of zinc, the upper part slowly colors a bluish-black, as in 

 Sterculia, The cell-wall below rapidly responds to the 

 action of phloroglucin, coloring wine-red and the light line 

 fainter, indicating lignin. Mattirolo shows a very striking 

 wine-red color in Tilia argeniea as well as in the lower 

 part of the cell, though I find the reactions not so strongly 

 marked in the light line, which may perhaps be attrib- 

 uted to the seed being somewhat unripe. The ripe seed of 

 Tilia Americana, agrees however with T. heterophylla . The 

 chlor-iodide of zinc test is just as positive. The whole broad 

 zone in the upper part of the cell-wall colors bluish-black, 

 which would seem to indicate that it consists partly of cellu- 

 lose, and that lignification has not proceeded so far. 



Ripe seed of Tilia Americana shows a very distinct lignin 

 reaction in the lower part of the Malpighian cell. The narrow 

 line just under the cuticle gives the reaction for lignin, but the 

 color is not so bright. Iodine alone colors the Malpighian 

 cells pale yellow. All parts are nearly alike at first, but longer 

 action causes the lower part to become darker in color. 

 When very dilute sulphuric acid is added the narrow light line 

 is conspicuously pale straw color. With stronger acid the 

 cell-wall is rapidly dissolved. Disintegration begins in the 

 region of the upper light line. The middle lamella becomes 

 black and resists its action longest. The walls of the Mal- 

 pighian cell are greatly thickened. 



Sterculiaceae, (Mattirolo 401. Caruel 312. Tschirch 



