SUMMARIES OF THE HISTOLOGIC CHARACTERS, ETC. 



325 



causing gelatinization, gives rise to conspicuousness of 

 an intermediate parent-phase. In 10 of the 47 starches 

 sulphuric acid developed sameness as the seed parent, and 

 in only 3 sameness as the pollen parent; potassium sul- 

 phocyanate developed sameness as seed parent in 6 of 

 the 33 reactions and sameness as the pollen parent in one 

 only; potassium sulphide, in 5 and 3, respectively; 

 strontium nitrate, in 5 and 0, respectively, and so on. 

 Certain other reagents exhibit a reversal of these pro- 

 pensities, as is noted particularly in the reactions of 

 chloral hydrate, sodium salicylate, and cupric chloride, in 

 which are found ratios 1:6, 1:4, and 2 : 3, respectively. 

 But in the intermediate, highest, and lowest columns, 

 many reactions are recorded that are closer to one than to 

 the other parent, and when these are added to the first 

 two columns, as in the summary of Table B, the pro- 

 pensities are in some instances practically unaltered, 

 in others accentuated, and ia others lessened or reversed. 

 It will be seen by comparing the two summaries that in 

 the first in the polarization reactions 11 are the same as 

 those of the seed parent and 11 the same as those of the 

 pollen parent; and in the second an almost equal division, 

 26 and 20, respectively. In the iodine reactions the 

 figures in the two tables are 16 : 12 and 25 : 18, respec- 

 tively — a ratio of 1:0.75 and 1:0.72, respectively; in 

 both of these reactions there being no essential difEerence 

 in the two tables. In the temperature of gelatinization 

 reactions the first table gives 7 : 3, and the second 39 : 18, 

 or ratios of 1 : 0.43 and 1 : 0.62, which show a slight 

 falling off in the latter. In the chloral-hydrate reactions 

 the first table shows a marked propensity to the pollen 

 parent, and the second a propensity to one about as much 

 as to the other; on the other hand, in the chromic- 

 acid reactions in Ihe first table there is shown a ratio 

 of 4 : 3 and in the second table 31 : 12, or in the latter 

 two and a half times the propensity to develop sameness 

 or closeness to the seed parent as to the pollen parent. In 

 other words, it seems that certain reagents, while having 

 definite propensities to develop a seed or pollen phase, 

 show varying degrees in their propensities to elicit same- 

 ness or closeness, some tending comparatively largely to 

 sameness and little to closeness, and others the reverse, 

 and so forth. Moreover, while a given reagent may have 

 a propensity to elicit sameness as^ one parent, it may 

 have at the same time a marked propensity to develop 

 closeness to the other parent in other starches, so that 

 in the summing up of the reactions with different 

 starches one may counterbalance the other. This is 

 illustrated in the chloral-hydrate reactions, in which it 

 is shown in the two summaries that the propensity to 

 elicit sameness to the pollen parents is 6 times greater 

 than to sameness to the other parent, while it is also 

 shown that because of a propensity to develop closeness 

 to the seed parent the former difEerence is dissipated and 

 an equal tendency is manifested to develop either the 

 seed or pollen parent phase, the ratio being 23 : 20. 

 It seems, therefore, that 'a better picture is to be obtained 

 of these propensities if thosei to sameness are included 

 with those to closeness. A cursory examination of the 

 figures of the first two columns of the latter table (the 

 other columns may be omitted to advantage and without 

 leading to misunderstanding), will render it evident 

 that the agents and reagents fall into 3 classes in accord- 



ance with their propensity to elicit sameness and close- 

 ness to the seed parent, sameness or closeness to the 

 pollen parent, or an absence of propensity to elicit either 

 parental relationship in preference to the other, and that 

 the classes merge into each other, as follows : 



Polarization 



Iodine 



Safranin 



Temperature of gelatinization 



Chloral hydrate 



Chromic aeid 



Pyrogallic acid 



Nitric acid 



Sulphuric acid 



Potassium iodide 



Potassium sulphocyanate .... 



Sodium sulphide 



Calciimi nitrate 



Uranium nitrate 



Strontium nitrate 



Barium chloride 



Mercuric chloride 



Copper nitrate 



Sodium salicylate 



Potassium hydroxide 



Cupric chloride 



Hydrochloric acid 



Gentian violet 



Potassium sulphide 



Sodium hydroxide 



Cobalt nitrate 



With very few exceptions the ratios appear to be 

 such as to make the assignment quite definite. From 

 these groups it will be seen that most of the agents and 

 reagents (17 of the 26) tend, most of them markedly, to 

 elicit the seed parent phase ; somewhat less than one-sixth 

 (4 of the 26), seldom markedly, tend to elicit the pollen 

 parent phase ; and the remaining less than one-fifth (5 of 

 the 26) tend with about or equal propensity to elicit one 

 or the other parent-phase. Perhaps, several that have 

 been assigned to the first group, especially chloral hy- 

 drate, should be transferred to the last group, and other 

 redistribution made. 



It seems from the foregoing data that the develop- 

 ment of the various parent-phases is dependent upon two 

 fundamental factors: One, inherent properties of the 

 starch by virtue of which different starches exhibit with 

 the same agent or reagent specific parent-phase reactions, 

 one starch reacting the same as the seed parent, another 

 the same as the pollen parent, another intermediate be- 

 tween the two parents, etc., as shown in preceding table; 

 and the other, inherent properties of the agents and 

 reagents by virtue of which, in association with the plas- 

 tic starch molecule, any parent-phase desired may be de- 

 veloped at will in any given starch. Inasmuch as there 

 are thus two factors which may tend in like or unlike 

 directions in the evolution of a parent-phase, it is clear 

 that the greatesit variations in these manifestations must 

 be expected in the reactions, both when there is a single 

 starch reacting with various reagents or a single reagent 

 reacting with various starches. 



