CYMBIDIUM. 



765 



The reaction with sodium sulphide begins immedi- 

 ately. Complete gelatinization occurs in about 98 per 

 cent of the entire number of grains and over 99 per cent 

 of the total starch in 1 minute; rare parts of grains re- 

 main; over 99 per cent of both the grains and total 

 starch in 2 minutes ; complete gelatiuization occurs in 3 

 minutes. 



The reaction with sodium salicylate begins imme- 

 diately. Complete gelatinization occurs in about 87 per 

 cent of the entire number of grains and 88 per cent 

 of the total starch in 1 minute; in over 99 per cent of 

 the grains and total starch in 2 minutes. 



The hilum, as in C. lowianum, is very distinct and a 

 bubble is usually formed there The lamellae are not so 

 distinct as in C. lowianum and later are obscured entirely 

 as in those grains. A narrow refractive band is formed 

 quickly about the margin of the grains before gelatiniza- 

 tion begins and remains there as gelatinizatiou proceeds. 

 Gelatinizatkm (unlike C. lowianum) begins usually at 

 several points on the margin at once, and occasionally 

 at the distal margin as in C. lowianum. The progress 

 of gelatinization from this beginning is essentially the 

 same as that in the grains of C. lowianum except that it 

 proceeds so rapidly that the starch of the interior of the 

 grain is torn into several large fragments, which fly 

 apart and then are gelatinized. The gelatinized grains 

 are large and more distorted, and retain less of the form 

 of the untreated grain than do those of C. lowianum. 



The reaction with calcium nitrate begins immedi- 

 ately. Complete gelatinization occurs in about 95 per 

 cent of the entire number of grains and 98 per cent of the 

 total starch in 30 seconds, and in 100 per cent of both 

 the grains and total starch in 1 minute and 15 seconds. 



The reaction with uranium nitrate begins immedi- 

 ately. Complete gelatinization occurs in about 8-1 per 

 cent of the entire number of grains and 97 per cent of 

 the total starch in 30 seconds; in 100 per cent of both 

 the grains and total starch in 1 minute. 



The reaction with strontium nitrate begins imme- 

 diately. Most of the grains are gelatinized in 15 seconds, 

 and over 99 per cent of both the grains and total starch 

 in 30 seconds. 



The reaction with cobalt nitrate begins immediately. 

 Complete gelatinization occurs in about 97 per cent of 

 the grains and 98 per cent of the total starch in 30 sec- 

 onds; in about 99 per cent of the grains and over 99 

 per cent of the total starch in 1 minute ; in 100 per cent 

 of both the grains and total starch in 2 minutes. 



The reaction with copper nitrate begins immediately. 

 Complete gelatinization occurs in all but rare grains in 

 30 seconds, and in all (100 per cent) of both the grains 

 and total starch in 45 seconds. 



The reaction with cupric chloride begins immedi- 

 ately. Complete gelatinization occurs in about 97 per 

 cent of the entire number of grains and 99 per cent of the 

 total starch in 1 minute; in about 99 per cent of the 

 grains and over 99 per cent of the total starch in 2 

 minutes; all but very rare smaller grains and parts 

 of the margin of rare grains gelatinized ; over 99 per cent 

 of both the grains and total starch in 5 minutes. 



The reaction with barium chloride begins imme- 

 diately. Complete gelatinization occurs in about 80 per 

 cent of the entire number of grains and 96 per cent of 

 the total starch in 5 minutes ; in about 94 per cent of the 



grains and 99 per cent of the total starch in 15 minutes ; 

 in about 97 per cent of the grains and over 99 per cent 

 of the total starcli in 30 minutes; little if any further 

 advance in 45 and GO minutes, respectively. (Chart 

 D618.) 



The hilum as in C. lowianum is distinct, but the 

 lamelte are not visible. Gelatinization, as in C. lowi- 

 anum, begins at the hilum and the progress is the same 

 as in those grains except that fissuration is not so deep 

 nor so extensive, and the marginal baud is not lamellated. 

 The gelatinized grains are not so large nor so distorted 

 as in (.'. lowianum. 



The reaction with mercuric chloride begins imme- 

 diately. Complete gelatinization occurs in about 92 per 

 cent of the grains and 98 per cent of the total starch 

 in 1 minute; in about 97 per cent of the grains and 

 over 99 per cent of the total starch in 2 minutes; in 

 all the grains (100 per cent) in 5 minutes. 



The hilum and lamella are moderately distinct, but 

 not so distinct as in C. lowianum. Gelatinization as in 

 C. lowianum begins at the hilum and progresses in the 

 same way as described under C. lowianum, except that the 

 starch immediately surrounding the hilum is not always 

 divided into granules, and when it is the granules are not 

 so coarse, not so numerous, while the marginal border 

 does not show a lamellated structure. The gelatinized 

 grains are large and slightly less distorted than in C. 

 lowianum, but retain the same amount of resemblance 

 to the form of the untreated grain. 



CYMBIDIUM KBURNEO-LOWIANUM (HYBRID). 



(Plate 24, fig. 144; Charts D 616 to D 618.) 



HISTOLOQIC PROPERTIES. 



In form the grains are usually simple and isolated, 

 with the exception of a few (a smaller number than in 

 either parent), which appear in aggregates of from 2 to 

 8 components. Compound grains, consisting of 2 com- 

 ponents, are rarely observed. The number of grains of 

 the isolated disaggregate type and of the aggregate type 

 is about the same, but there are less of the former than in 

 C. lowianum, but more than in C. eburneum, and con- 

 siderably more of the latter than in C. lowianum, but 

 somewhat less than in C. eburneum. Well-marked pres- 

 sure facets are more numerous than in C. lowianum, but 

 somewhat less than in C. eburneum. The surface of the 

 grain is usually regular, and such irregularities as may 

 occur are due to the same causes as noted for both parents. 

 There is slightly less irregularity than in C. lowianum, 

 but somewhat more than in C. eburneum. The con- 

 spicuous forms among the isolated grains of the disaggre- 

 gate type are nearly round, pyriform, round, ovoid, ellip- 

 soidal, and rounded triangular. These grains are some- 

 what more broadened, as in C. lowianum, but of about 

 the same size ; and they are of much the same proportions, 

 but considerably larger than most of the grains of C. 

 eburneum. The conspicuous forms of the grains of the 

 isolated aggregate type are both low and high dome- 

 shaped (with more of the former than in C. lowianum, but 

 about the same as in C. eburneum), with squared, pointed 

 or diagonal distal end, bell- jar-shaped, polygonal, and 

 ovoid with concave distal end. Very rare large isolated 

 grains of the disaggregate type are scattered among those 

 already noted. These grains are usually pyriform, ovoid, 

 or low triangular, and they are slightly more numerous 



