SUMMARIES OF PLANT CHARACTERS, ETC. 



341 



the tissue groups as do the latter from each other. Com- 

 paring the tissue characters and starch reactivities 

 (Table I, Summary 3), it is found that the former 

 show distinctly lower percentages in regard to sameness 

 as the seed parent, pollen parent, and both parents ; 

 markedly higher percentages in regard to intermediate- 

 ness and characters that are developed in excess of paren- 

 tal extremes ; and a distinctly lower percentage developed 

 in deficit of parental extremes. It seems obvious from 

 this that the figures recorded in any one of these modes 

 of investigation can not be taken as an index of what 

 is to be found by another. If the percentages of the 

 tissue characters and starch characters are charted ( Chart 

 P 9 ) it will be seen that there is only a very gross, if 

 any, correspondence between the two curves. If three 

 curves are constructed to show the macroscopic, micro- 

 scopic, and reaction data respectively (Chart F 10), a 

 modified picture is presented. It will be noted that the 

 macroscopic and microscopic curves show similarities 

 and that neither appears to be related to the starch curve. 



The comparative degrees of influence of each of the 

 parents in determining ihe characters of the hybrid 

 varies not only with the different sets, but also in the 

 percentages of macroscopic and microscopic characters 

 in each set. Table H, Summary 2, gives a summary of the 

 sameness and inclination of the reaction-intensities of 

 the starches of hybrids to one or the other parent or both 

 parents. Table I, Summary 4, presents similar data of 

 the macroscopic and microscopic plant characters. Tak- 

 ing the macroscopic and microscopic characters together, 

 it will be found that there is marked dominance of the 

 seed parent in Ipoma sloteri (58:23) and Cypripe- 

 dium lathamianum inversum (GO: 43), and of the pollen 

 parent in Lcelia-Cattleya canliamiana (31 : 61), and that 

 there is little dominance of either parent in Cymbidium 

 eburneo-lowianum (41 : 35), Miltonia bleuana (39 : 47), 

 Cypripedium lathamianum (39:48), and Cypripedium 

 nit ens (41 : 47). In none of these hybrids is there noted 

 in the tissue characters the extreme dominance recorded 

 in the reaction-intensities and histological properties of 

 some of the hybrids in the starch investigation, but such 

 dominance will undoubtedly be brought out in researches 

 with other parents and hybrids. 



In summing up the numbers and percentages of the 

 tissue characters and starch reaction-intensities that are 

 the same as or inclined to the seed parent, the pollen 

 parent, and to both parents, and which are as close to one 

 as to the other parent, respectively, it is found that the 

 different hybrids show the widest variations in direction 

 and degree (Table I, Summary 6, and Table G). Thus, 

 in Ipomcea sloteri the ratio of macroscopic charac- 

 ters that are the same as or inclined to the seed parent 

 to those that are the same as or inclined tn the pollen 

 parent is about 2 : 1, while of the microscopic characters 

 it is almost 3 : 1. In Lcelia-Cattleya canliamiana the 

 ratios are about 1 : 2 and 1 : 2 respectively. In Cym- 

 bidium eburneo-loirianum the ratios are l 1 /^ : 1, and 1 : 1, 

 respectively. In Dendrobiwn cybele the ratios are 1 : 3 

 and 1 : 1, respectively, and so on. In the case of the 

 starches the ratios are far more varied, ranging from 

 23 : at one extreme to : 25 at the other extreme, with 

 great variations in between. In summing up the figures 

 and percentages for the tissues and comparing them with 

 the corresponding figures for the starches, it is found that 



the figures for the combined macroscopic and micro- 

 scopic characters that are the same as or inclined to the 

 seed parent and the pollen parent, respectively, are 36.8 

 and 36.9, while for the starches they are 42.7 and 32.4. 

 Of characters that are the same as those of both 

 parents the figures for the tissues and starches are 5.2 and 

 13.8, respectively. In group of characters first stated the 

 figures are almost the same in the first couple, while in 

 the second couple the first figure is about one-third higher 

 than the second. In the second group the first figure is 

 small in comparison with the second, this probably being 

 due to the fact that in the study of the tissue characters 

 many characters that were found in the hybrid to be the 

 same or practically the same as the characters in the 

 parents were not recorded. Of characters that are as 

 close to one as to the other parent the tissue character 

 percentage is 21.1, while that of the starches is 11.1. 

 Finally, among the tissue characters, 73.7 per cent are 

 the same as or inclined to the seed or the pollen parent ; 

 and among the starch characters 75.1 per cent, or prac- 

 tically the same. 



In case of two sets of parents and hybrids (Cym- 

 bidium and Miltonia), studies were made coincidently 

 of both tissue and starch characters, but unfortunately 

 in one (Cymbidium) the reactions of the starches were 

 with few exceptions so very rapid that satisfactory data 

 for differential purposes were not obtained. These data 

 are summarized in Tables I, 3, and 5, and F, 47 and 

 48, and also in Charts F 3, F 5, F 11, and F 12. Ee- 

 ferring to the characters and character-phases of Cym- 

 bidium eburneo-lowianum it will be apparent upon com- 

 parison of the data pertaining to the several parental- 

 phases (Chart F3) that the percentages of macroscopic 

 characters are smaller than those of the microscopic 

 characters that are the same as those of the seed parent, 

 and which are developed in excess and in deficit of 

 parental extremes ; but larger among those which are 

 the same as those of the pollen parent and of both parents, 

 and which are intermediate. Hence, there are inver- 

 sions of the curves in the chart. The quantitative differ- 

 ences between the plant and the reaction characters vary 

 in the several parental-phases (Chart Fll), the differ- 

 ences being distinct among the characters that are the 

 same as those of one or the other parent or both parents, 

 marked among those which are developed in excess or 

 deficit of parental extremes, and very marked among 

 those which are intermediate. While there are some 

 correspondences in the percentages and curves of the 

 macroscopic and microscopic data, there is no corre- 

 spondence between these and the starch reaction-inten- 

 sity curve. In fact, there seems to be a tendency to 

 inverse rather than direct relationship. In Miltonia 

 bleuana the macroscopic and microscopic figures and 

 curves differ in some respects less and in others more 

 than in Cymbidium eburneo-lowianum (Chart F12). 

 The percentages of the macroscopic characters are higher 

 than those of the macroscopic characters among the 

 characters that are the same as those of the seed parent 

 and the same as those of the pollen parent, but lower 

 among the characters that fall under the other four 

 parental-phases, so that here also there is inversion of the 

 two curves. The percentages and curves of the starch 

 reaction-intensities bear, as in the foregoing hybrid, 

 apparently no relationship to either macroscopic or 



