342 



SUMMARIES OF PLANT CHARACTERS, ETC. 



microscopic character curve, and here also it appears as 

 though there is a tendency to inverse rather than direct 

 relationship. While the starch reaction-intensity data 

 in Cymbidium are of little value, for reasons stated, the 

 data of MUtonia are to be regarded as being quite as 

 dependable as those of either macroscopic or microscopic 

 characters. 



In further comparisons to bring out specifically 

 the comparative influences of the seed and the pollen 

 parent on the properties of the hybrids (Table I, Sum- 

 mary 5, Charts F 11 and P 12) it will be found in Cym- 

 bidium eburneo-lowianum that the macroscopic and 

 microscopic percentages and curves tend to correspond- 

 ence in their courses with varying degrees of separation, 

 and also to inversions in their positions. The percentages 

 of macroscopic characters compared with those of micro- 

 scopic characters are lower among the characters that are 

 the same as those of the seed parent, that are highest and 

 that are lowest; and higher among those that are the 

 same as those of the pollen parent, that are the same as 

 those of both parents and that are intermediate. 



Comparing now the starch-reaction data with the 

 foregoing, it will be seen that while the percentages 

 and curves of the tissue data have some correspondence, 

 the starch data and curve appear to be quite independ- 

 ent, the starch curve being higher than the tissue curve 

 in respect to characters that are the same as those of 

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

 those which are lowest; and zero in characters that are 

 the same as those of the pollen parent, intermediate and 

 highest. In MUtonia bleuana the macroscopic and micro- 

 scopic values and curves are quite different from the 

 preceding. The curve of the macroscopic characters is 

 higher than that of the microscopic characters among the 

 characters that are the same as those of the seed parent 

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

 in the other four parental designations. The starch curve 

 here is also very variant, bearing no relationship to the 

 tissue curves. It is intermediate between the macro- 

 scopic and microscopic curves in regard to characters 

 that are the same as those of the seed parent and that 

 are lowest, lower in characters that are the same as those 

 of the pollen parent and that are intermediate, and 

 higher in characters that are the same as those of both 

 parents and that are highest. In Cymbidium eburneo- 

 lowianum (Table I. Summary 5) 30 per cent of the tissue 

 characters are the same as those of one or the other parent 

 or both parents; 44.5 per cent intermediate; and 25.4 per 

 cent developed in excess or deficit of parental extremes. 

 The starch reactions show 50.1, 0, and 50 per cent, re- 

 spectively, the figures in the several columns differing 

 markedly from those of the tissues. In MUtonia bleuana 

 the figures for the tissues are 26.2, 35.1 and 38.6, respec- 

 tively; and for the starch 23, 3.8, and 73.1, respectively. 



The comparative degrees of influence exerted by 

 each parent on the properties of the hybrid are shown 

 in Table I, Summary 6, and presented in chart form in 



(harts V 1 ! and F 15. In Cymbidium eburneo-lowianum, 

 in the macroscopic characters the seed parent has exerted 

 a much greater influence than the pollen parent, but in 

 the microscopic characters very little more than the pollen 

 parent. Jn MUtonia bleuana, in the macroscopic charac- 

 ters the seed parent is distinctly more potent, but in the 

 microscopic characters the pollen parent is the more 

 potent, the values being practically reversed. Summing 

 up the macroscopic and microscopic characters it is 

 found that in Cymbidium eburneo-lowianum the seed 

 parent is but little more potent than the pollen parent 

 (37.3: 31.8 per cent), and that in MUtonia blueana the 

 seed parent is decidedly less potent than the pollen 

 parent (34.2:41.2 per cent). As to the starches in 

 Cymbidium eburneo-lowianum the influences of the seed 

 parent are far greater than those of the pollen parent 

 as shown by the ratio of 15.4: 3.8; and in MUtonia blue- 

 ana the difference is very much greater, the ratio lure 

 being 77 : 7.7 — in the former 4 times greater and in the 

 latter almost 10 times greater. Little or no importance, 

 however, is to be attached to the data of the starch of 

 Cymbidium for reasons already given. 



In the histological examinations of the starches it was 

 found that the starch of Cymbidium eburneo-lowianum 

 in the form of the grains, character of the hilum, lamella;, 

 and size is closer, as a whole, to the seed parent ; and in 

 eccentricity of the hilum and ratio of length to width of 

 the grains closer, as a whole, to the pollen parent. In 

 the qualitative reactions it is in all respects closer to the 

 seed parent. In MUtonia bleuana the starch is in the 

 form of the grains, character of the hilum, and character 

 of the lamella? closer, as a whole, to the seed parent ; but 

 in eccentricity of the hilum and size of the grains it is 

 closer, as a whole, to the pollen parent. In all of the 

 qualitative reactions it is closer to the seed parent. 



Apropos of intermediateness as a criterion of hy- 

 brids, it is worth while to compare the percentages of 

 microscopic and macroscopic characters and starch reac- 

 tion-intensities that are intermediate and non-interme- 

 diate. These data are given in Tabic I, Summary 7, by 

 which it will be seen that of 264 macroscopic characters 

 recorded 56.4 per cent are intermediate and 43.6 oer cent 

 non-intermediate; of the 695 microscopic characters, 38.2 

 per cent are intermediate and 61.8 per cent non-interme- 

 diate ;and of the 1,018 starch reaction-intensities, 23.2 per 

 cent are intermediate and "6.8 per cent non-intermediate. 



The data recorded, are so numerous and of such a 

 character that considerable space could be devoted to 

 their study, but this seems unnecessary because they 

 have been so thoroughly systematized and clearly pre- 

 sented in tables and charts as to be instantly understood 

 and readily available for any who may be particularly 

 interested in any or all of the various phases represented ; 

 nor is it necessary, because such detailed consideration 

 as has been given meets the requirements of the objects 

 of the research. 



