63 



it on cooling. But they did not give tlie starch reactions with iodine-sulphuric acid, methyl 

 violet, and gentian violet. (This might be a form of glycogen, since Claude Bernard found 

 a glycogen in paralyzed muscles that gave a blue reaction with iodine, and because glycogen 

 is an important constituent of the human organism, while starch heretofore has been found 

 only as a transient food-stuff that is confined to the alimentary tract.) 



A starch-like substance known as "Floridean or Rhodophycean starch" has been 

 observed in a number of Floridecp. This body, which seemingly is not identical in different 

 plants, has been examined by Van Tieghem (Compt. rend., 1865, lxi, 804), Belzung 

 (Ann. d. Sci. uat. Bot., Ser. vii, v, 179; quoted by Zimmermann, loc. cit.), Hansen (Mitth. 

 a. d. Zool. Station, z. Neapel, 1893, xi, 276, 283), Golenkin (Alogologische Notizen, 1894, 4) 

 and Burns (Flora, 1894, Erg. bd., 159). Van Tieghem found that the grains of this 

 body agree in most of their chemical properties with ordinary starch, and that in the 

 polarizing microscope they showed a similar cross or interference figure. With iodine, 

 however, a yellow-brown or brownish-red reaction was obtained. Belzung states that 

 the starch of many Floridecc, especially the young grains, yields a blue reaction. 



The " Phseophycean starch" described by Schmitz (Die Chromatophoren der Algen, 

 Bonn, 1882, 154; Jahrbiicher f. wissensch. Botanik, xv, 1) is in the form of colorless bodies 

 that are found in the cytoplasm. They do not yield a color reaction with iodine, and it is 

 held by Berthold (Jahrbiicher f. wissensch. Botanik, xiii, 569) that such bodies do not exist. 



Paramylon or paramylum grains have been examined by Hebs (Untersuch. a. d. bot. 

 Institut z. Tiibingen, 1883, i, 233), Schmitz (Jalirbuch. f. wissensch. Botanik, 1884, xv, 111), 

 Schimper {ibidum, 1885, xvi, 199), and Zopf (Schenk's Handbuch, Bd. in, Hefte 2, 1). These 

 grains have been observed in several Exiglencc and other low organisms, but there is doubt 

 as to their actual character. They have been seen as disk-shaped, rod-shaped, and ring- 

 shaped forms, and in some instances they have been found to be lamellated after being sub- 

 jected to the action of certain swelling media, but the lamellation differed from that of ordi- 

 nary starch-grains, inasmuch as it was in the form of complete concentric rings or plates 

 without a common center or liilum. They do not yield a color reaction with iodine, and 

 they differ in their behavior towards certain swelling and solvent reagents, and certain stains. 



Glycogen, which occurs in both plant and animal life, chiefly in the latter, is so closely 

 related to starch as to be called "animal starch." In the saccharification of glycogen, 

 dextrins appear as intermediary bodies, as in the saccharification of starch (see Tebb, 

 page 153). With iodine it yields an orange to a reddish-brown or wine-color reaction, 

 according to the strength of solution and form of the glycogen, the color cUsappearing on 

 heating and reappearing on cooling, as with starch. It is soluble in water, forming an 

 opalescent solution, and it exists in the living tissues usually as colorless, refractive bodies. 

 Errera (Bot. Zeit., 1886, 316; Zeit. f. w. Mikrosk, iii, 277) found that glycogen is widely 

 distributed in fungi, in which it seemingly replaces starch, inasmuch as cliromatophores 

 are absent from these organisms and therefore probably no starch formed, and since it 

 seems to serve the purpose of a reserve food. It is also formed, sometimes very abun- 

 dantly, in yeast cells, as shown by Errera (RecueO de ITnstitut botanique, Bruxelles, 

 1906; Compt. rend., 1885, ci, 253), Laurent (Jahresbr. ii. Giihrungsorg., 1900, i, 54), Meiss- 

 ner (Centralbl. f. Bakt., 1900, ii, 6), Cremer (Ber. d. d. chem. Gesellsch., 1899, xxxii, 

 2062) and Pavy and Bywaters (Jour. Physiology, 1907, xxxvi, 149). In large fungi, as 

 in Phallus, Clautriau (Jahresb. ii. Giihrungsorg., 1895, vi, 51) has shown that glycogen 

 disappears rapidly dm-ing growth, it being altered in the same manner as starch under 

 similar conditions in phanerogams. 



Other substances that bear a more or less close relationship to starch are cellulin 

 bodies discovered by Pringsheim (Ber. d. d. botan. Gesellsch., 1883, 288) in the hyphte of 

 Saprolegniacea. These bodies occur in the form of spherical, circular, or polyhedral granules 

 which are occasionally lamellated. They do not yield a color reaction with iodine. Noll 



