SUMMARIES OF THE HISTOLOGIC CHARACTERS, ETC. 



285 



hybrids from the same cross (see Brunsdonna) ; but 

 here again in the final summing up there is usually 

 found to be a distinct majority of the reactions leaning 

 to on© or the other parent. It is unfortunate that very 

 frequently the data have not been recorded in accord- 

 ance with the plan adopted at the outstart of the research 

 so as to leave no doubt in each character or character- 

 phase of the parental relationships of the hybrid, such as 

 was pursued in making the quantitative determinations. 

 Owing to this defect it is necessary to present these 

 summaries in a modified tabular form, and with the view 

 particularly of showing the fluctuating relationships of 

 the hybrids to the parents. In the preparation of the 

 tables that follow (Tables C 1 to C 17), the properties of 

 the hybrids in their parental relationships have been 

 considered collectively in designations or groups that 

 are indicated by the divisions of the tables, those of form 

 being taken as one designation, those with a given rea- 

 gent as one designation, and so on. The plus sign is to 

 be interpreted as meaning that in the final summing up 

 of the data of each designation the hybrid in its unit- 

 character and unit-character-phase bears, on the whole, 

 a closer relationship to the parent indicated at the head 

 of the column. The mtntts sign is, of course, the nega- 

 tive correlative of the former ; while the plus-minus sign 

 indicates that the hybrid resembles in degree one as much 

 as the other parent. In the last column the terms excess 

 and deficit mean that a unit-character or unit-eharacter- 

 phase is developed in excess or deficit of parental ex- 

 tremes ; individual means that a unit-character or unit- 

 eharacter-phase has been discovered in the hybrid that 

 was not observed in either parent. 



Certain apparently minor peculiarities have been dis- 

 regarded in this tabulation. In some instances it is 

 entirely arbitrary whether we regard a given property as 

 being developed in excess or deficit of parental extremes. 

 Thus, if the grains of the hybrid be more irregular, or 

 the resistance to reagents greater, than those of the 

 parents, are we to look upon the difference as being an 

 expression of increased or decreased development ? Ten- 

 tatively, such differences have been taken as represent- 

 ing increased development; and, if there be less irregu- 

 larity or less resistance, the opposite. It is obvious that 

 these tables indicate merely very grossly certain promi- 

 nent phases of hybrid and parental relationships, and that 

 the context must be studied therewith in order that the 



qualitative and quantitative fluctuations of the hybrid in 

 relation to each parent can properly be understood. In 

 the several sets of tables that follow, the symbols 9 , c? 

 and 9-S are used as sex designations to indicate nearer 

 the seed parent, nearer the pollen parent, and equally 

 related to both, respectively. The symbol © in Tables 

 F, 1 to 50, and H, 1 to 26, indicates that the reactions 

 are too fast or too slow for satisfactory differentiation, 

 or that because of fluctuations in the courses of gela- 

 tiaization there is either no satisfactory differentiation 

 or sufficiently definite inclination to either parent. The 

 data of the quantitative reactions are taken from the 

 various tables of the reaction-intensities expressed by 

 the percentage of total starch gelatinized at definite time- 

 intervals that constitute the third section of each sum- 

 mary in Chapter III, and also tabulated in modified ar- 

 rangement in Section 4 of this chapter. These data have 

 also been presented in the form of charts in Chapter IV. 



It is important to note that in the studies of the quali- 

 tative reactions the reagents selected varied somewhat 

 in number and kind in the different sets of parents and 

 hybrids, and that in the formulation of these tables the 

 quantitative reactions given are limited to those of the 

 reagents used to elicit the qualitative reactions. Hence, 

 in the summing up in these tables of the relationships of 

 the reactions of the hybrids to those of the parents there 

 may seem to be some discrepancies when the figures are 

 compared with those of Tables E, 1 to 22, F, 1 to 50, 

 and H, 1 to 26. For instance, in the quantitative reac- 

 tions of Brunsdonna sanderm alba it vrill be noted that 

 of the 8 reactions with the chemical reagents none is like 

 that of the seed parent, pollen parent, or both parents, 

 1 is intermediate, 1 is higher than that of either parent, 

 and 6 are lower than those of either parent. When, 

 however, all of the 21 reactions are summed up it is 

 found (Table F, 1) that 4 are the same as those of seed 

 parents, none the same as those of the pollen parent, 1 

 the same as those of both parents, 5 intermediate, 3 

 higher than those of the parents, and 13 lower than those 

 of the parents. 



The limited quantitative data given in Tables C 1 

 to C 17 are mainly for comparisons with the qualitative 

 reactions with the same reagents, the data of this kind 

 being tabulated in full in tables E, F, and H. Limited 

 comment only is necessary in explaining this series of 

 tables. 



(a) Brunsdonna sanderm alba {same parentage as following hybrid). 

 Table C 1. — Brunsdonna sanderm alba. 



