III. On the existence of amorphous starch in a new tuberaceous fungus

Abstract

Amorphous starch (including under that term all starch not in the form of the ordinary starch-granule) is rare in the vegetable world. Until the present year Schleiden was the only botanist by whom it had been noticed, and his observations have been doubted by Sanio, Caspary, and Schenk. He (Schleiden) states (Grundzüge, i. 181) that he has seen amorphous starch in the form of a thin pasty layer in the cells of the albumen of Cardamomum minus , in Sarsaparilla , and in the rhizome of Carex arenaria . Sanio has just published the result of some experiments made by him upon the cells of the epidermis of Gagea lutea . Upon applying a solution of iodine to these cells, he observed a fine flocculent blue precipitate in their interior. The blue colour was confined to the fluid contents of the cells, the primordial utricle and the nucleus becoming yellow under the iodine. Another observer, Dr. Schenk, has lately noticed the occurrence of starch in a state of solution in the epidermal cells of the stem, leaves, and other parts of Ornithogalum nutans and lanceolatum . These cells were found to contain (besides nuclei) a thick homogeneous fluid. Tincture of iodine coloured the fluid first wine-red, then violet, and finally indigo-blue; and the fluid at the same time lost its homogeneous nature, and became finely granular and flocculent.