CALANTHE. 



771 



The reaction with chromic acid begins immediately. 

 Complete gelatinizatiou occurs in about 7 per cent of the 

 entire number ol' grains and 64 per cent of the total 

 starch in 5 minutes; in about 6-1 per cent of the grains 

 and 95 per cent of the total starch in 15 minutes; in 

 about 98 per cent of the entire number of grains and 

 over 99 per cent of the total starch in 30 minutes; in 

 about 99 per cent of both the grains and total starch in 

 45 minutes; rare lenticular grains are not completely 

 gelatinized in GO minutes. (Chart D 620.) 



The reaction with this specimen is difficult to follow 

 since many oxalate needles are present, and during solu- 

 tion they cause an evolution of bubbles which as they 

 break produce a current that carries the grains out 

 of the field; furthermore solution of the grains takes 

 place following gelatiuization and hence if a current 

 draws them from the field it is difficult to estimate in a 

 new field as to how many have been dissolved. The 

 preparation must consist of a very thin layer of starch 

 and must be constantly kept under observation. If a 

 comparatively small number of needles are present, the 

 bubbles may remain comparatively small and hence pre- 

 vent currents from carrying the grains out of the field. 

 During solution the grains become very light and motion 

 may occur, causing grains to leave the field. It is diffi- 

 cult to estimate the total starch gelatinized because the 

 grains, with exception of a narrow border, appear as 

 though partially gelatinized and under the polariscope 

 show an exceedingly low or no degree of polarization. 

 Scattered among these grains are a few of very regular 

 outline and moderately high degree of polarization ; these 

 grains are quite resistant to gelatinization. The reaction 

 begins in the grains (with main body of apparently 

 uneven density) by the appearance of irregular fissures 

 which break this region into refractive masses and finally 

 into granules. Two fissures usually start from one point 

 which gradually appears to be a hilum in the grains of 

 even density throughout, later these may either form 

 clusters of delicate branches breaking the main body 

 into irregular masses, or the two main branches may 

 extend around the main body until they meet at the 

 distal end, the main body undergoing gelatinization 

 previous to the narrow very refractive border. In elon- 

 gated grains the border at the distal margin is gelatinized 

 before the proximal end and sides; and in solution is 

 broken first at this point, later one side is frequently 

 dissolved more quickly than the other. The gelatinized 

 grains are somewhat swollen and are not generally dis- 

 torted; a narrow border which is very refractive and 

 generally consists of but one lamella is very resistant and 

 frequently remains unless the grains become dissolved. 

 Previous to solution this lamella becomes striated and 

 breaks into linearly arranged granules. 



The reaction with pyroyallic acid begins in 1 minute. 

 Complete gelatinization occurs in about 10 per cent of 

 the entire number of grains and 30 per cent of the total 

 starch in 5 minutes; in about 26 per cent of the grains 

 and 60 per cent of the total starch in 15 minutes; in 

 about 34 per cent of the grains and 92 per cent of the 

 total starch in 30 minutes ; in about the same percentage 

 of the grains and 95 per cent of the total starch in 45 min- 

 utes ; in about 52 per cent of the grains and 96 per cent 

 of the total starch in GO minutes. (Chart D 621.) 



The reaction with nitric acid begins immediately. 

 Complete gelatinizatiou occurs in about 27 per cent of 

 the entire number of grains and 74 per cent of the 

 total starch in 5 minutes; in about 50 per cent of the 

 grains and 82 per cent of the total starch in 15 minutes; 

 in about 52 per cent of the grains and 87 per cent of the 

 total starch in 30 minutes; in about 54 per cent of the 

 grains and 90 per cent of the total starch in 45 minutes ; 

 in about 59 per cent of the grains and 95 per cent of 

 the total starch in 60 minutes. (Chart D622.) 



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 93 per cent of 

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

 starch in 3 minutes; in more than 99 per cent of the 

 grains and total starch in 5 minutes. (Chart D 623.) 



The reaction with Injdrochloric acid begins imme- 

 diately. Complete gelatinization occurs in about 22 per 

 cent of the entire number of grains and 84 per cent of 

 the total starch in 5 minutes; in about 41 per cent of 

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

 minutes; in about 50 per cent of the grains and 95 per 

 cent of the total starch in 30 minutes; in about 71 per 

 cent of the grains and 96 per cent of the total starch in 

 45 minutes; in about 77 per cent of the grains and 97 

 per cent of the total starch in 60 minutes. (Chart 

 D624.) 



Gelatinization in the majority of grains begins at 

 the margin, usually the distal end when this region 

 is clearly defined, and is frequently accompanied with 

 considerable distortion. The narrow refractive border 

 is generally crenate and following the gelatinization at 

 the indented points may become broken into concave bril- 

 liant segments. Two fissures may proceed from the 

 hilum of scattered broadly triangular grains which are 

 homogeneously refractive and have but a slightly sinuous 

 outline; these fissures proceed distalwards and form the 

 boundary between a narrow refractive border and the 

 mesial region, which region is more quickly gelatinized, 

 parts of the refractive border especially at and near the 

 proximal end being quite resistant. A few medium- 

 sized grains, which are very refractive, are found in which 

 1 or 2 very sharply defined fissures proceed from the 

 hilum ; these grains are much more resistant than those 

 previously mentioned. At the end of the experiment 

 (60 minutes) the majority of the grains are gelatinized 

 and many have been dissolved, while many more are in 

 various stages of disintegration. Scattered among these 

 are a few with a broad, refractive border bounding a mass 

 of refractive granules. The grains are much swollen 

 and undergo considerable distortion during gelatiniza- 

 tion and disintegration. 



The reaction with potassium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 10 per 

 cent of the grains and 78 per cent of the total starch in 5 

 minutes; in about 18 per cent of the grains and 88 per 

 cent of the total starch in 15 minutes; in about 22 per 

 cent of the grains and 90 per cent of the total starch in 

 30 minutes ; in about 27 per cent of the grains and 93 per 

 cent of the total starch in 45 minutes ; in about 29 per 

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

 60 minutes. (Chart D 625.) 



The hilum becomes visible in some grains in which 

 hitherto it was not demonstrable, and more distinct in 

 others in which it could be demonstrated before treat- 



