826 STARCHES OF MARANTACE^. 



The reaction with pyrogaUic acid begins at once; several are gelatinized in 10 seconds, nearly 

 all in 25 seconds, and all in 35 seconds except rare, large, triangular grains, in which the reaction 

 may take 9 minutes. The reaction is qualitatively the same as in M. arundinacea with the follow- 

 ing exceptions: First, in the small dome-shaped, round, etc., grains a bubble appears at the hilum, 

 but it is quite small and does not enlarge so much. Second, in the few large grains under observa- 

 tion the fissxu-es are much more clear-cut, the lamellae more sharply defined and striated, and the 

 refractive granules more brilliant, with more frequent linear arrangement during the progress of the 

 reaction. The gelatinized grains are swollen but retain the general shape of untreated grain. 



The reaction begins immediately with ferric chloride. A few grains are gelatinized in a minute, 

 about two-fifths in 2 minutes, nearly all in 5 minutes, and all but rare resistant grains in 6 minutes, 

 in which the reaction is usually complete in 10 minutes, rarely 17 minutes. The more resistant 

 grains are the larger forms. The reaction is qualitatively the same as in M. arundinacea, and the 

 method usually observed is the second type described for that species. The following exceptions 

 are observed : First, the border formed around the grain is rather dull. Second, the starch of the 

 larger grains is broken into rather large fragments, the lamellae of which are very sharply de- 

 fined and as they disorganize refractive granules appear in linear arrangement, which often do 

 not completely gelatinize. The gelatinized grains are swollen but retain the general shape of the 

 untreated grain. 



Reaction begins immediately with Purdy's solution. Only a few scattered grains are gelatinized 

 in 5 minutes, about one-twentieth in 15 minutes, about one-ninth in 30 minutes; no further progress 

 in an hour. The reaction is qualitatively the same as in M. arundinacea with the following excep- 

 tions: First, since the majority of the grains are very different in form, the arrangement of the 

 fissures is not the same; in the dome-shaped grains one coarse, clean-cut cleft passes from the hilum 

 to the comers of the distal margin, and numerous delicate fissures radiate from all other points of 

 the hilum. In round grains the fissures radiate like the rays of a star, often about five larger ones 

 with delicate ones between; during gelatinization these fissures extend to the periphery of the grain, 

 breaking the resistant starch into fairly large fragments. Second, in the large grains similar in shape 

 to those of M. arundinacea, much more refractive lamellae appear at varying points on the grain 

 and (as they gelatinize) a larger mass of more brilliant, refractive granules develops, which more 

 often have a linear arrangement. The gelatinized grains are swollen, but retain the general shape 

 of the untreated grain. A few refractive granules and sometimes fairly large fragments of sohd 

 starch are found in the otherwise gelatinized grains. 



STARCH OF MARANTA MUSAICA. (Plate 89, figs. 633 and 534. Chart 350.) 



Histological Characteristics. — In form the grains are usually simple and are generally isolated, 

 with a few aggregates and compound grains. Pressure facets are occasionally observed. Most 

 grains are either slightly or quite irregular, much more so than in M. arundinacea. The irregularities 

 appear as noted for M. arundinacea, but there is a greater variation in the contour of the different 

 sides of a grain and the presence of a secondary set of lamellae placed at varying angles to the pri- 

 mary set is very frequently observed. The conspicuous forms are irregular pyriform, sometimes 

 with flattened sides, triangular, clam-shell-shaped, elongated ovoid, and ellipsoidal; also knob- 

 shaped, club-shaped, oyster-shell-shaped, imperfect quadrangular with rounded angles, elongated 

 cone-shaped, and grains of indefinite form. The broadened grains are elongated ovoid, having the 

 distal end narrow and pointed, when viewed on edge. The other grains are not flattened. 



The hilum is frequently not demonstrable, but it may be observed as a clear, round, non-re- 

 fractive spot, usually eccentric about one-sixth to one-ninth, rarely one-twelfth, of the longitudinal 

 axis. The hilum is rarely fissured, but sometimes a short, transverse cleft is found at this region. 

 The hilum is much less distinct and the absence of clefts at this region is much more noticeable than 

 in M. arundinacea. 



The lamella; are quite distinct and form circular rings near the hilum, but follow the outline of 

 the grain quite closely at other points, especially in the triangular and shell-shaped grains. In some 

 grains the lamellae of one set vary in outUne and direction, while very often a secondary set is placed at 

 different angles to the primary set. The lamellae are mostly fine, but often one to three rather coarse 

 ones are interspersed among them between the hilum and the distal margin. A band of less distinct, 

 very fine lamellae is sometimes observed at the distal margin. On the larger grains often 28 to 32, 

 occasionally 36 to 40, lamellae are counted. The appearance of a large addition on the grain of a 



