BEGONIA. 



707 



The reaction with cobalt nitrate begins in very rare 

 grains in 1 minute. Complete gelatinization is not 

 observed in any grains in 5 minutes, and even after the 

 grains have been treated i'or 15, 30, 45, and 60 minutes 

 only rare grains are much a Heeled by the reagent, so that 

 complete gelatinization occurs in much less than 0.5 per 

 cent of the entire number of grains and total starch in 

 60 minutes. (Chart D 522.) 



The reaction with copper nitrate begins in rare grains 

 in 2 minutes. Complete gelatinization occurs in less than 

 0.5 per cent of the entire number of grains and total 

 starch in 5 minutes; in. less than 0.5 per cent of the 

 grains and total starch in 15 minutes; slight advance 

 in 30 minutes; in less than 0.5 per cent of the grains 

 and 1 per cent of the total starch in 45 minutes; in 

 about 0.5 per cent of the grains and 2 per cent of the 

 total starch in 60 minutes. (Chart D 523.) 



The reaction with cupric chloride begins in rare 

 grains in 1 minute. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains and 

 total starch in 5 minutes ; little if any advance is observed 

 in 15, 30, 45, and 60 minutes, respectively. (Chart 

 D524.) 



The reaction with barium chloride begins in rare 

 grains in 2 minutes. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains 

 and total starch in 5 minutes; little if any further ad- 

 vance in 15, 30, 45, and 60 minutes. (Chart D 525.) 



The reaction with mercuric chloride begins in rare 

 grains in 2 minutes. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains and 

 total starch in 5 minutes; little if any further advance 

 occurs in 15, 30, 45, and 60 minutes, respectively. 

 (Chart D 526.) 



Begonia ensign (Hybrid). 



(Plate 21, fig. 126; Charts D 527 to D 532.) 

 Histologic Properties. 



In form the grains are always simple as in both 

 parents, and isolated as in B. socotrana. They are usually 

 as regular as in B. double light rose, and any irregulari- 

 ties are due to the same causes as in that starch, except 

 that some grains have protuberances as in B. socotrana. 

 The conspicuous forms are ovoid, elongated ovoid, ellip- 

 tical, and nearly round. The additional forms are quad- 

 rilateral with much rounded angles, rod-shaped, and 

 triangular. The grains, as in B. double light rose, are not 

 flattened. In form B. ensign shows a closer relationship 

 to B. double white rose than to B. socotrana. 



The hilum is as distinct as in B. double light rose, and 

 more distinct than in B. socotrana. It is no more often 

 fissured than in B. double light rose, and the fissures 

 have the same forms as in that starch. The hilum is 

 never centric as it sometimes is in B. double light rose, 

 but is eccentric from 0.42 to 0.16, usually 0.25, of the 

 longitudinal axis; this is 0.06 more eccentric than in 

 B. double light rose, and 0.07 less than in B. socotrana. 

 In the character of the hilum, B. ensign shows a closer 

 relationship to B. double light rose, but in the degree of 

 eccentricity there is a somewhat closer relationship to B. 

 socotrana. 



The lamella; are more distinct than in B. double light 

 rose and have the same character and arrangement as 

 in that grain, except that they are often wavy in outline 



and always more distinct at the distal than at the proxi- 

 mal end, as in B. socotrana. The number counted on tin- 

 larger grains varies from 28 to 45, usually 33. In the 

 character of the lamella: B. ensign shows a somewhat 

 closer relationship to B. double light rose than to />'. 

 socotrana, but in number the reverse. 



In size the grains vary from the smaller which are 

 6 by 6/x, to the larger which are 46 by 22/t, in Length 

 and breadth. The common sizes are 28 by 16/t and SO 

 by 20^,. In size and proportion of the common-sized 

 grains B. ensign is somewhat closer to B. double light rose, 

 but in those of the larger grains closer to B. socotrana. 



Polariscopic Properties. 



The figure is distinct and varies from moderately to 

 very clear-cut as in B. socotrana. The lines cross at an 

 acute angle which does not vary greatly in the different 

 grains as in B. socotrana. They are more often bent 

 and bisected than in either parent, and in the iirst re- 

 spect more closely resemble B. double light rose and in 

 the last B. socotrana. 



The degree of polarization varies from moderate to 

 high (value 67), 7 units more than in B. socotrana and 

 3 units less than in B. double light rose. There is rarely 

 any variation in a given aspect of an individual grain 

 as in B. double light rose. 



With selcnile the quadrants are as clear-cut as in 

 B. socotrana. They are less unequal in size than in 

 B. socotrana, but more than in B. double light rose; and 

 are more irregular in size than in either parent, but in this 

 respect more closely resemble B. double light rose than 

 B. socotrana. The colors as in B. double light, rose are 

 usually pure, but a somewhat smaller number of grains 

 have a greenish tinge. 



In the character of the figure B. ensign shows a 

 closer relationship to B. socotrana, and in the degree of 

 polarization and the appearances with selenite to B. 

 double light rose. 



Iodine Reactions. 

 With 0.25 per cent Lugol's solution the grains all 

 color a light to moderate blue-violet (value 40), 5 units 

 less than in B. double light rose and 10 units more than 

 in B. socotrana. With 0.125 per cent Lugol's solution 

 the grains all color a light blue-violet, less than B. double 

 light rose, but much more than in B. socotrana. After 

 heating in water until the grains are all gelatinized, and 

 then treating with a 2 per cent Lugol's solution, the 

 gelatinized grains are usually colored moderately light, 

 a few light, and a few a deep indigo as in B. double light 

 rose; and the solution a deep indigo as in B. double light 

 rose. If the preparation is boiled for 2 minutes and then 

 treated with an excess of a 2 per cent Lugol's solution, 

 the grain-residues all color a light to moderate indigo 

 at the proximal end, the capsules a deep violet, and the 

 solution a very deep indigo, as in B. double light rose. 

 Qualitatively and quantitatively the reactions with iodine 

 show a closer relationship to B. double light rose than to 

 B. socotrana. 



Aniline Reactions. 



With gentian violet the grains all color lightly at once, 

 and in 30 minutes they are light to moderately colored 

 (value 30), 5 units less than in B. socotrana and 10 

 units less than in B. double light rose; the greater num- 



