H.EMANTHUS. 



433 



starch in 20 minutes; and in all in 60 minutes. (Chart 

 D97.) 



A small bubble appears at the hilum which very rarely 

 is inclosed within a fissure, and it is very persistent, 

 expanding very little if any previous to expulsion. The 

 lamellas do not become any more distinct, but a border is 

 formed which is slightly more refractive than the rest of 

 the grain. In the grains with either a centric or slightly 

 eccentric hilum gelatinization begins at both ends, and 

 then the process later is usually more rapid from one end 

 than the other, and as it approaches the hilum either a 

 clear narrow space or a delicate fissure is furrowed 

 through the resistant area as the bubble is expelled. In 

 the grains with a quite eccentric hilum gelatinization 

 begins at the distal margin and advances slowly toward 

 the hilum; just previous to the expulsion of the bubble 

 a mesial fissure proceeds towards the proximal end which 

 becomes gelatinized previous to the sides nearby, hence, 

 even in such grains a narrow baud on either side of the 

 hilum is the most resistant starch. 



The gelatinized grains are swollen and distorted so 

 that they do not resemble the untreated grain. Either 

 partial or complete solution may follow gelatinization. 



The reaction with calcium nitrate begins in rare 

 grains in 30 seconds. Complete gelatinization occurs in 

 about 0.5 per cent of the entire number of grains and in 

 about 1 per cent of the total starch in 5 minutes; in 

 about the same percentage of each in 15, 30, 45, and 60 

 minutes, respectively. A few grains are quickly gela- 

 tinized but apart from this there is extremely little 

 effect. ( Chart D 98.) 



The reaction with uranium nitrate begins in rare 

 grains in 30 seconds. Complete gelatinization occurs in 

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

 than 1 per cent of the total starch in 5 minutes ; in about 

 the same percentage of grains and 1.25 per cent of the 

 total starch in 15 minutes; and in about the same per- 

 centage of each in 30, 45, and 60 minutes, respectively. 

 A very few grains are quickly gelatinized but there is 

 very little action beyond this. (Chart D 99.) 



The reaction with strontium nitrate begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and in 

 about 2 per cent of the total starch in 5 minutes ; in about 

 the same percentage of grains and 3 per cent of the total 

 starch in 15 minutes; and in about the same percentage 

 of each in 30, 45, and 60 minutes, respectively. (Chart 

 D 100.) 



The reaction with cobalt nitrate begins in rare grains 

 in 1 minute. Complete gelatinization occurs in a few 

 grains and the process has begun in but few, less than 

 0.5 per cent of both the entire number of grains and the 

 total starch, in 5 minutes; very little progress in 15 min- 

 utes ; complete gelatinization occurs in about 0.5 per cent 

 of the entire number of grains and 1 per cent of the 

 total starch in 30 minutes; about the same in 45 and 

 60 minutes. (Chart D 101.) 



Gelatinization usually proceeds through the mesial 

 portion of the grains, preceded by the formation of deli- 

 cate fissures in some of the grains. The entire margin is 

 for a time resistant, but finally in complete gelatinization 

 the proximal end proves the most resistant. When the 

 grains are considerably elongated the process may begin 



at one or both ends (when the hilum is almost centric) 

 but eventually proceeds more rapidly from the end which 

 is farthest from the hilum. 



The reaction with copper nitrate begins in rare grains 

 in half a minute. Complete gelatinization occurs in very 

 rare grains and the process has begun in much less than 

 0.5 per cent, of both the entire number of grains and of 

 the total starch, in 5 minutes ; slight progress in 15, 30, 

 45, and 60 minutes, until at the end of this period com- 

 plete gelatinization occurs in about 0.5 per cent of the 

 entire number of grains and in about 1.5 per cent of the 

 total starch. (Chart D 102.) Gelatinization proceeds 

 through the mesial portion along the course of fissures, 

 the distal end being gelatinized before the proximal end. 



The reaction with cupric chloride begins in very rare 

 grains in 1 minute. Complete gelatinization was not 

 observed in any grains and the process has begun in but 

 rare grains, much less than 0.5 per cent of both the entire 

 number of grains, and the total starch in 5 minutes ; com- 

 plete gelatinization occurs in rare grains and the process 

 is begun in but rare grains in 15 minutes; no apparent 

 progress in 30, 45, and 60 minutes, respectively, at the 

 end of which period less than 0.5 per cent of both the 

 entire number of grains and the total starch is gelatinized. 

 (Chart D 103.) Gelatinization proceeds through the 

 mesial region along the fissures, the distal margin being 

 gelatinized much more rapidly than the proximal end. 

 In some grains the distal margin is gelatinized, accom- 

 panied by some extension but no fluting of this distal end 

 before the mesial portion towards the hilum is much 

 affected. 



The reaction with barium chloride begins in very 

 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 ; and in about the same per- 

 centage of each in 15, 30, 45, and 60 minutes, respec- 

 tively. (Chart D 104.) 



The reaction with mercuric chloride begins in rare 

 grains in 1 minute. Complete gelatinization occurs in 

 about 0.5 per cent of the entire number of grains and 1.25 

 per cent of the total starch in 5 minutes ; in about 1 per 

 cent of the grains and 0.5 per cent of the total starch in 

 15 minutes; about the same in 30, 45, and 60 minutes, 

 respectively. (Chart D 105.) There are a few scattered 

 grains in this preparation that are quickly gelatinized, 

 while almost all are very resistant. 



ILEMANTHUS 11AGNIFICUS (POLLEN PARENT). 

 (Plate 3, fig. 17; Charts D 85 to D 105.) 



HISTOLOOIC PROPERTIES. 



In form the grains are xisually simple and isolated. 

 There are more small aggregates of 2, 3, or 4 grains than 

 in H. leathering, and there are compound grains consist- 

 ing of 2 to 4 components inclosed in a number of second- 

 ary lamellae which have not been seen in H. katherinw. 

 The components of the compound grains are linearly or 

 pyramidally arranged or, when there are 4 or more in a 

 compact group, they are separated from one another by 

 fissures which do not extend to the margin of the grain. 

 The grains are somewhat more frequently irregular in 

 form than in H. leathering, but there is not much differ- 

 ence between the two starches in this respect. The 

 iregularities are due to the following causes: (1) To a 



