Pammel — Anatomical Characters of Seeds of Leguminosae. 121 



acid and iodine; (2) amyloid, which colors blue with iodine; 

 (3) plant mucilages, which swell on the addition of water and 

 do not color with iodine. Von Mohl's views (183) did not 

 differ essentially from those expressed by Payen. Nageli 

 (187, 209) applied the term (1) amyloid to those carbo- 

 hydrates which color blue with iodine, e. g. starch grains, the 

 thick- walled cells of ScJiolia^ Hymenaea^ Tamarindus^ and 

 Mucuna, the endosperm cells of CalUandra; (2) the violet 

 modifications of amyloid, as the starch grains in the medullary 

 rays of Chelidonium, the endosperm of Ixia and Gladiolus, 

 the intercellular mucilages of Florideae and the mucilages 

 of Usnea and Mamalina ; (3) mesamylin, which colors yel- 

 low or not at all, e. g., the bast fibers of many plants like 

 Linum, Cannabis, and Urlica divaricata; (4) disamylum, 

 which is not colored or else colors yellow or intensely golden 

 yellow, or brownish-yellow, e. g. endosperm of palms, Galium, 

 Coffea, and tStrycJinos. Nageli makes a brief reference to 

 the mucilage of Leguminosae. 



Frank (335) who investigated the mucilage of sev- 

 eral orders of plants, speaks of the reserve cellulose in the 

 endosperm of Tropaeolum. The chemical nature of reserve 

 cellulose has been investigated by many writers. Reiss 

 (432), Hoffmeister (377), Miss Cooley (316), Schulze (441), 

 Winterstein (473), Cross and Bevan (320), Zimmermann 

 (294a), Behrens (302), and Tschirch (265, 193-208. /. 191- 

 208) treat of the vegetable mucilages. 



The gelatinized membranes are distinguished from the 

 ordinary cell- walls by their physical properties. They swell 

 strongly in the presence of water. They agree in their per- 

 centage composition with cellulose, CeHioOs, but they differ 

 from it in their chemical reactions as well as among them- 

 selves. Some of them are colored blue with iodine ( amyloid ) , 

 as in the cotyledons of Tamarindus, and endosperm of Trop- 

 aeolum. Others color blue only on the addition of sulphuric 

 acid or chlor-iodide of zinc, as in the thick-walled endo- 

 sperm cells of Gymnocladus, Gleditschia, Lespedeza, and 

 many others where endosperm is present in the form of re- 

 serve cellulose. 



Some of the reserve celluloses are colored yellow, others 



