SUMMARIES OP THE HISTOLOGIC CHARACTERS, ETC. 



309 



Eeaction-intensities of Each Hybeid Starch. 



(Tables F, Parts 1 to 50 and Summary; G and H, Parts 1 to 26 and 

 Summaries 1 and 2.) 



In Chapter I particular reference was made to the 

 recognition of intermediateness as one of the primary 

 criteria of hybrids, this applying not only to macroscopic 

 and microscopic characters of plants, but also to the 

 microscopic characters of starches. Intermediateness of 

 starches was therein shown to have been recorded by 

 MacFarlane (page 7) in Bibes, Bryanthus, and Hedy- 

 chium, and by ]3arby shire (page 8) in Pisum. Mac- 

 Farlane states that in Bibes grossularia, B. culverwellii 

 (hybrid) and R. nigrum the starch grains of the three 

 are very variable in size, but in the iirst the largest 

 are 7 pi and the average ifi; in the third the largest are 

 3/i and the average 1%/*; and in the second the largest 

 are 5/a and the average Sfi. In Menziesis empertriformis 

 var., Bryanthus erectus (hybrid) and Rhododendron 

 chamwcistus he found that in the third the starch grains 

 are 4/* across the largest, though most are from 2fi to 

 3ju,; in the first the largest granules are 6/t across, and 

 in all cases they are larger than in the third ; and in the 

 second the size of the granules falls rather toward the 

 third. In Hedychium gwrinerianum, R. sadlerianum 

 (hybrid), and H. coronarium he notes that in the first 

 each starch grain is a small triangular plate, measuring 

 10/A to 12/A, from hilum to base, and that the lamination 

 is not very distinct ; in the third each grain is ovate, or in 

 some cases tapered rather finely to a point at the hilum, 

 38/* to 60/i long from hilum to base, and the lamination 

 is very marked; in the second "the grains may best 

 be described if we suppose a rather reduced one of the 

 first parent to be set on the reduced basal half of one of 

 the latter. The lamination also is more pronounced than 

 in the first, less so than in the second." Darbyshire 

 records that the round starch grain of the Fi generation 

 is a blend between the type of grain of the round pea 

 (the potato-shaped) and the type of grain of the wrinkled 

 pea (the compound) in respect to the three characters: 

 length-breadth-index, distribution of compoundness, 

 and degree of compoundness. While these data are very 

 meager they are concordant and in harmony with the 

 dictum of intermediateness of histologic and naked-eye 

 characters of hybrids. 



In the present research it was found in the studies of 

 the histologic peculiarities that in case of every hybrid 

 there are certain characters that are intermediate, the 

 degree of intermediateness varying from mid-interme- 

 diateness to almost identity with one or the other parent. 

 Mid-intermediateness was found to be, on the whole, far 

 less common than a degree of intermediateness that 

 closely approached one or the other parent; identity 

 of a given character with that of one or the other parent 

 was quite common; development of a given character 

 or character-phase in excess or deficit of those of both 

 parents quite frequent; and the appearance of individ- 

 ualities in the hybrid that are not seen in either parent 

 was by no means rare. In fact, it seems clear that the 

 more in detail these studies are carried out the farther 

 we are taken from the conception of generality of inter- 

 mediateness of the properties of the hybrid. The records 

 of the histologic peculiarities of the starches are fully 

 supported by those of the histologic and macroscopic 

 characters of plants as set forth in this chapter and in 



Part II, Chapter II, and also by the qualitative and 

 quantitative reactions of the starches throughout the 

 entire range of agents and reagents as shown by the data 

 that are represented especially in Chapter III and Part 

 II, Chapter I. In preceding parts of the present chap- 

 ter various tabular statements exhibit from different 

 aspects parental relationships of the hybrids. It seems 

 desirable at this point to tabulate the reaction-intensi- 

 ties of the hybrids with reference to sameness to one or 

 the other parent or both parents, intermediateness, and 

 excess and deficit of development in relation to the 

 parents, so that one may see at a glance, as it were, the 

 relative importance of the several phases of parent-charac- 

 ter development in regard to the reaction-intensities of : 

 (a) Each hybrid starch with different agents and rea- 

 gents, which wiU. exhibit particularly the differences in 

 the behavior of each starch in comparison vnth the reac- 

 tion of other starches in the presence of the same agents 

 and reagents; (6) each hybrid starch as regards sameness 

 and inclination in its properties in relation to one or 

 the other or both parents, which will exhibit particularly 

 the comparative potencies of the parents in determining 

 the properties of the starch of the hybrid; and (c) all 

 of the hybrid starches with each agent and reagent, 

 which will exhibit particularly the independence of the 

 behavior of each agent and reagent, and also all of the 

 hybrid starches with each agent and reagent, as regards 

 sameness and inclination in the properties to one or 

 the other parent or both parents, which will exhibit 

 particularly the independent tendencies of each agent 

 or reagent to elicit definite and specific parent-phases. 

 While all of these tabulations are most intimately cor- 

 related, each brings out certain features with marked 

 accentuation in a form not elicited by the others. 



Eeaction-intensities oe Bach Hybrid Starch with 

 Different Agents and Eeagents. 



(Tables F, Parts 1 to 50 and Simimary.) 



It is to be noted in an examination of the results 

 formulated in the accompanying table that in only 32 of 

 the 50 hybrids recorded all of the 26 reactions, 16 record- 

 ed only 10 reactions, and 2 only 13 reactions. Taking up 

 this table, even a most cursory examination will indi- 

 cate the very wide variations of the numerical values of 

 the 6 phases of parent-development of the different 

 starches in their parental relationships, and each part of 

 the table is different from every other part and is specifi- 

 cally distinctive of the hybrid, even in the cases of hybrids 

 that have resulted from the same cross, as in Brunsdonna 

 sanderce alba and B. sanderm (Table F, 1 and 2), and 

 Narcissus poeticus herrick and N. poeticus dante (Table 

 F, 16 and 17) . Moreover, in one hybrid intermediateness 

 may be relatively so very conspicuous that the other 

 phases sink into insignificance, while in another this 

 phase may be as markedly conspicuous by its almost or 

 entire absence, and so on in other tables with the other 

 phases. It is also very obvious that the hybrid is less 

 apt to be characterized by a prominence of intermediate- 

 ness than by a conspicuousness of highest or lowest de- 

 velopment or even of other phase of parental relationship. 



The several parts of this table may, for convenience of 

 study, be grouped into four classes: (1) those in which 

 one of the phases of development very markedly domi- 

 nates the others, one-half or more of the reactions being 



