SUMMARIES OF THE HISTOLOGK CHARA< I I.I 



309 



Reaction-intensities of Each Bybeid Staech. 



(Tallies F, Parts 1 to 5U and Summary; G and II, Parts 1 to 20 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 nol only to macro i op ■■ 



:iiul microscopic characters of plain-. bu1 also to the 

 microscopic characters of starches, [ntermediateni 



tarches was therein shown to have been recorded bj 

 MacParlane (page 7) in Ribes, Bryanthus, and Hedy 

 chium, and by Darbyshire (page 8) in Pisum. Hac- 

 Farlane states thai in Ribes grossularia, /.'. culver 



(hybrid) and A', nigrum the starch grains of the three 

 are very variable in size, but in the first the largesi 

 are 7/x and the average !/<.; in the third the largest are 

 3/t and the average 1%/t; and in the second the largest 

 are 5/x and the average 3p. In Menziesis empertriformis 

 \ar.. Bryanthus erectus (hybrid) and Rhododendron 

 chamcecistus he found that in the third the starch grains 

 are 4fj. aeross the largest, though must are from 2/i to 

 3/a; in the first the largest granules are (J/1 aeross, and 

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

 second the size of the granules falls rather toward the 

 third. In Hedychium gardnerianum, II. sadlerianum 

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

 each starch grain is a small triangular plate, measuring 

 H'/i to 12/*, from hilum to base, and that the lamination 

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

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

 32ft. to 6G> long from hilum to base, and the lamination 

 is very marked; in the second "the grains ma. 

 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 F, 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 compound ness, 

 and degree of componndness. 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 rase 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-intcrmediateness was found to be, on the whole, far 

 less common than a degree of intermediateness that 

 closely approached one or the other parent; idi 

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

 was quite common; development of a given chai 

 or character-phase in excess or d I those of both 



parents quite frequent : and the appearance Of individ- 

 ualities in the hybrid that are noi seen in either pa 

 was by no means rare. In fact, it seem- 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 rei 

 of the histologic peculiarities of the starches are fully 

 supported by those of the histologic and macroscopic 

 characters of plants as sel forth in this chapter and in 



[I, i M. and also by the qualil 



quant it.it i . broughout the 



e range of agents and r< 



111 and 

 1 1, < ihapter I. In precedin 

 ter various tabular statements exhibit from dim 



- parental relationshi] 

 desirable at this point, to tabulate th 

 ties of the hybrids « ill. ne or 



the other parent or both parents, intermedial . 



- and deficit of developmenl in relation to the 

 parents, so that one ma ; 

 relative importam e of thesi 

 ter development in i i the reaction-inten 



(a) Each hybrid starch with diffen i 

 gents, which will exhibit particularly the differem 

 the behavior of each starch in comparison with 

 tion of other starches in the presem e of the same a. 

 and reagents; (b) each hybrid starch as rej 

 and inclination in it- properties in relation to on o 

 the other or both p i ich will exhibit particularly 



the comparative potem ies of the parents in determining 

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

 of the hybrid stari hi with each a 

 which will exhibit particularly the in nee of the 



or of ea and reagi nt, and also all of the 



hybrid starches with each agent and reagent, a 

 sameness and inclination in th 



the other parent or both parent-, which will exhibit 

 particularly the independent tend 

 or reagent to elicit definite and i parent-ph 



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 othi 



Reactiox-inti OF Bach Hybrid Starch with 



Different Agents and Reagents. 



(Tallies F. Parts 1 to 50 and Sunimai 



It is to - d ted in an examination of th 

 formulated in the accompanying table that in only 3 

 the 50 hybrids recorded .ill of the 26 reactions, I 

 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 relationship-, and cadi part of 

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

 cally distinctive of the hybrid, even intl of hybrids 

 thai have resulted from the same cross, as in Brunsdonna 

 ind />'. sandi rn (Table F, 1 and 2 i. and 

 errick and N. poelicus dtintr (Table 

 F, 16 and 17). Moreover, in one hybrid intermedia: 

 may be relatively so ver, us That the other 

 sink into insignificance, while in another this 

 phase may be a- markedly cons:.;, uous by its almost or 

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

 • It is ,.' that the hybr 



d by a prominence of intermediate- 

 ■' l ian by a conspicuousness of high -t or lowest de- 

 velopment or even of other phase of pai 



The several parts of this table may. I 

 study, be grouped into four el in which 



one of the phases of development very markedly domi- 

 the others, one-half or more of the r- 



