PHAIUS. 



747 



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

 the total starch in 1 minute; all grains are completely 

 gelatinized with the exception of parts of rare grains, 

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

 total starch in 1 minute and 30 seconds. (Chart D 579.) 



The hilum, as in P. grandifolius, becomes very dis- 

 tinct and a bubble is not so frequently formed there. 

 The lamellae are even less distinct than in P. grandifolius, 

 and very much less distinct than in P. wallichii. A 

 broad, refractive band is found as in the parents. Grela- 

 tinization begins at the proximal end and progresses as 

 in P. grandifolius, except that not all the grains have 

 granules formed and persisting at the proximal end, and 

 when such granules are present they are not so coarse 

 as in P. grandifolius. The gelatinized grains are large, 

 nearly transparent, and very thin-walled, but as in P. 

 grandifolius they retain some of the form of the un- 

 treated grain. In this reaction P. hybridus shows a 

 closer relationship to P. grandifolius than to P. wallichii. 



The reaction with potassium hydroxide begins imme- 

 diately. Complete gclatinization occurs in about 91 

 jper cent of the entire number of grains and 94 per cent 

 of the total starch in 15 seconds ; in about 99 per cent of 

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

 30 seconds. (Chart D 580.) 



The hilum becomes as distinct as in P. grandifolius, 

 and also the lamellas, which persist nearly to the end 

 of the reaction as in P. grandifolius. A refractive band 

 about the margin can be noted, and the starch constitut- 

 ing this is not gelatinized until after that of the rest 

 of the grain as in P. grandifolius. Gelatinization begins 

 at the hilum, and only occasionally at the distal end as in 

 P. wallichii. From this point the progress is the same 

 in most of the grains as in P. grandifolius, and in a few as 

 in P. wallichii. The gelatinized grains, as in P. grandi- 

 folius, are large and usually considerably distorted, espe- 

 cially at the distal end, but they retain considerable of 

 the forms of the untreated grain. In this reaction P. 

 hybridus is qualitatively closer to P. grandifolius than to 

 P. wallichii. 



The reaction with potassium iodide begins imme- 

 diately. Complete gelatinization occurs in about 39 per 

 cent of the entire number of grains and 82 per cent of 

 the total starch in 5 minutes ; in about 82 per cent of the 

 grains and 92 per cent of the total starch in 15 minutes; 

 in about 93 per cent of the grains and 95 per cent of the 

 total starch in 30 minutes; in about 95 per cent of the 

 grains and 98 per cent of the total starch in 45 minutes ; 

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

 total starch in 60 minutes. (Chart D 581.) 



A bubble appears about as frequently as in P. grandi- 

 folius, and more frequently than in P. wallichii, and it 

 enlarges to greater size in more grains than in both 

 parents. Gelatinization rarely begins at the proximal 

 end, accompanied by a small distention of the capsule at 

 that part, this occurring less frequently than in P. gran- 

 difolius. This method was not observed in P. wallichii. 

 The lamella? become more sharply defined and striated as 

 in both parents, but the definition is more quickly lost 

 than in P. grandifolius, but hardly so rapidly as in P. 

 wallichii. The fissures more frequently are the same as 

 in P. grandifolius, though branching towards the distal 

 margin is more common than in this species; but not 



nearly so frequently branched as in P. wallichii. A group 

 of delicate fissures forms between the 2 main oblique fis- 

 sures much more frequently than in P. grandifolius, 

 followed by the more rapid gelatinization of the mesial 

 portion, often with the appearance of only slightly refrac- 

 tive granules in the area around the hilum. The gran- 

 ules of the mesial region are less refractive than in P. 

 grandifolius, and the mean is somewhat more than in P. 

 wallichii. The marginal border at the proximal end and 

 sides is more frequently moderately broad than in either 

 parent, and less often breaks into linearly arranged gran- 

 ules than in P. grandifolius, and about as in P. 'wallichii. 

 The lamellae toward the distal margin are less frequently 

 disorganized into linear granules previous to gelatiniza- 

 tion than in P. grandifolius, and about as in P. wallichii. 



The gelatinized grain is swollen and distorted, more 

 closely resembling that of P. grandifolius, though less 

 frequently telescoped throughout the depressed proximal 

 end; and less distorted throughout the margin than in 

 P. wallichii. The border at the proximal end and sides is 

 less resistant, as well as the group of quite refractive 

 granules around the hilum, than in P. grandifolius, but 

 the granules more frequently remain than in P. wallichii. 

 The gelatinized grains, as in the parents, do not resemble 

 the form of the untreated grain. These reactions are 

 closer to those of P. grandifolius than to those of the 

 other parent. 



The reaction with potassium sulphocyanate begins 

 immediately. Complete gelatinization occurs in about 89 

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

 of the total starch in 5 minutes; in about 96 per cent of 

 the grains and 99 per cent of the total starch in 15 min- 

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

 cent of the total starch in 30 minutes. (Chart D 582.) 



The reaction begins and proceeds as in both parents, 

 the minute steps more closely following those of P. gran- 

 difolius. The lamellas are not quite so sharply defined as 

 in P. grandifolius, 'but decidedly more than in P. wal- 

 lichii. Fissures do not generally form, as in P. grandi- 

 folius, but not in P. wallichii. A broader refractive band 

 at the proximal end and sides bounds the mesial gela- 

 tinized region more often than in either parent. The 

 mesial portion is broken down into moderately refrac- 

 tive granules, often with a more refractive group in the 

 area around the hilum ; the hilum is not quite so refrac- 

 tive as in P. grandifolius, but more refractive and the 

 group is more frequently present than in P. wallichii. 

 The lamellae forming the refractive border at the proxi- 

 mal end and sides gradually become sharply defined and 

 striated, but usually gelatinize without breaking into 

 refractive granules ; this border is more resistant than in 

 most grains of P. wallichii. The gelatinized grains are 

 swollen and distorted, usually less at the proximal end 

 than in both parents. They do not resemble the untreated 

 grain as in both parents. The reactions are closer to 

 those of P. grandifolius than to those of the other parent. 



The reaction with potassium sulphide begins imme- 

 diately. Complete gelatinization occurs in about 81 per 

 cent of the grains and 95 per cent of the total starch in 

 2 minutes; in about 95 per cent of the grains and over 

 99 per cent of the total starch in 5 minutes. (Chart 

 D 583.) The reaction is so rapid that the minute steps 

 can not be determined as in both parents. 



