124 Trans. Acad. Sci. of St. Louis. 



F. Contents of schizogenic excretory reservoirs. 



1. Cycadaceae, Marattiaceae, some Stercttliaceae, Araliaceae. 



2. In schizo-lysigenetic cavities. Rind of Laminaria stipites. 



G. In lysigenetic passages. 



1. Bark of Acacia, Moringa, Cochlospermum. 



2. In bark and woods, Prunus Cerasus, Herminiera. 



3. In pith and medullary rays, Tragacanth. 

 i. Unknown, gum of Sterculia urens. 



III. Amyloid. Secondary tiiickening of cell- walls. Colors blue with iodine. 

 Seeds of Tropaeolum, Hymenaea Courbaril, Tamarindus, Paeonia, 

 Balsamina, Primulaceae {Primula, Androsace, Anagallis, Glaux), Iris 

 acuta, Cyclamen neapolitanum, Asparagus, Gladiolus segetum, and 

 cambium of many trees. 



It will be seen from the above that plant mucilages are 

 diverse as to orisiu and occurrence. The mucilage in the 

 testa of Theohromaceae^ Tiliaceae, and /StercuUaceae, was 

 formerly regarded as belonging to cell contents. It arises 

 from the cell membrane, which finally swells and forms a muci- 

 laginous mass. The occurrence of mucilage in the cell is less 

 common than its production from the secondary cell mem- 

 brane. The mucilage in the parenchyma cells of Allium 

 Gejoa, Scilla maritima, and the very large mucilage cells of 

 Salep and the tissues of Symphytum, the gelatinous cell- walls 

 of Spirogyra, the mucilage of Cliondrus crispus, the mucilag- 

 inous cell walls of Saccharomyces cerevisiae, and the hyphae 

 of many fungi are all familiar examples of one form and 

 another in which these mucilages occur. Table F shows 

 the reactions of the mucilaginous endosperm in the order 

 Legumiiiosae. 



Different opinions have been expressed as to how the mate- 

 rial has been laid down. Miss Cooley found in Liliaceae 

 and some related orders that it is laid down as secondary 

 structure during the ripening of the seed, and this is also true 

 for Leguminosae. 



Reserve Cellulose and associated reserve matters. — 

 Tschirch (265,453) makes the statement that reserve cellu- 

 lose occurs where the cells of cotyledons are thin-walled and 

 contain no starch or where it is sparingly found. In Legumi- 

 nosae this holds true in general, e. g. Gymnocladus canadensis^ 

 Gleditschia triacanthos, Cassia marylandica^Ceratoniasiliqua, 

 Parki7isonia aculeata and Robinia Pseudacacia. In Trifolium 



